energy
(ˈɛnədʒɪ)
[ad. late L. energīa, Gr. ἐνέργεια, f. ἐνεργής, f. ἐν + ἔργον work. Cf. Fr. énergie. Senses 1 and 2 belong to ἐνέργεια as used by Aristotle, whereas sense 5 answers to that of Gr. δύναµις.]
1. a. With reference to speech or writing: Force or vigour of expression.
[This sense (found in late L. and in Romanic) is originally derived from an imperfect understanding of Aristotle's use of ἐνέργεια (Rhet. iii. xi. §2) for the species of metaphor which calls up a mental picture of something ‘acting’ or moving. In mod. use it blends with 3.]
| [1581 Sidney Def. Poesie (Arb.) 67 That same forciblenes, or Energia, (as the Greekes cal it) of the writer.] 1599 Thynne Animadv. 42 The frenche Hollybande, not vnderstandinge the true energye of our tongue. a 1696 Holder (J.), When animated by elocution [Speech] acquires a greater life and energy. 1729 Stackhouse Body Divin. iv. i. §2 These are all of them terms of a peculiar energy. 1845 Whately Rhet. (1850) 203 The transposition of words which the ancient languages admit of, conduces, not merely to variety, but to Energy. 1847 Emerson Repr. Men, Shaks. Wks. (Bohn) I. 357 The Liturgy, admired for its energy and pathos. |
† b. transf. Impressiveness (of an event).
Obs.| 1764 Harmer Observ. ii. 7 This thunder..added considerably to the energy of this event [Saul's inauguration]. |
2. a. Exercise of power, actual working, operation, activity;
freq. in philosophical language.
† Formerly also
concr: The product of activity, an effect.
| a 1626 Bacon (J.), They are not effective of any thing, nor leave no work behind them, but are energies merely. 1642 H. More Song of Soul Gloss., Energie..is the operation, efflux or activity of any being: as the light of the Sunne is the energie of the Sunne, and every phantasm of the soul is the energie of the soul. 1644–52 J. Smith Sel. Disc. viii. v. (1821) 399 Their life is nothing else but a strong energy of fancy and opinion. 1646 Sir T. Browne Pseud. Ep. II. v. 87 The conceited remedy..carryeth often the honour of the capitall energie, which had no finger in it. 1744 Harris Three Treat. (1841) 18 Call every production, the parts of which exist successively..a motion or an energy: thus a tune and a dance are energies. 1798 Bay Amer. Law Rep. (1809) I. 23 Naturalization had a retrospective energy. 1833 I. Taylor Fanat. ii. 42 The transition of the passions from momentary energies to settled dispositions. 1859 Sir W. Hamilton Lect. (1877) II. xxi. 25 The faculty of which this act of revocation is the energy, I call the Reproductive. |
† b. Effectual operation; efficacy.
Obs.| a 1719 Smalridge (J.), Beg the blessed Jesus to give an energy to your imperfect prayers. 1725 Pope Odyss. xx. 226 Blows have more energy than airy words. |
3. Vigour or intensity of action, utterance, etc. Hence as a personal quality: The capacity and habit of strenuous exertion.
| 1809–10 Coleridge Friend (1865) 37 To lose the general and lasting consequences of rare and virtuous energy. 1839 Thirlwall Greece V. 110 The prudence and energy displayed at this critical juncture by Agesilaus. 1841–4 Emerson Ess. Prudence Wks. (Bohn) I. 93 The poet admires the man of energy and tactics. 1855 Macaulay Hist. Eng. III. 726 He took his measures with his usual energy and dexterity. 1856 Kane Arct. Expl. I. xi. 121 When the hatches were opened, the flame burst out with energy. 1856 Froude Hist. Eng. I. i. 71 Henry, with the full energy of his fiery nature, was flinging himself into a quarrel. |
4. a. Power actively and efficiently displayed or exerted. Sometimes in
pl. in same sense.
| 1665 Glanvill Sceps. Sci. xii. 66 If this motive Energie..must be called Heat..I contend not. 1813 Sir H. Davy Agric. Chem. (1814) 185 Soils..which act with the greatest chemical energy in preserving Manures. 1849 M. Somerville Connex. Phys. Sc. Introd. 2 Impress the mind with some notion of the energy that maintains them [the heavenly bodies] in their motions. Ibid. iii. 15 The disturbing energy of the planets. 1860 Tyndall Glac. i. §7. 51 Struggle with the slow energy of a behemoth. 1865 Dickens Mut. Fr. II. 24 The united energies of two horses, two men, four wheels, and a plum-pudding carriage dog. 1870 E. Peacock Ralf Skirl. II. 1 Throwing all their energies into worldly concerns. |
b. pl. Individual powers in exercise; activities.
| a 1742 Bentley (J.), How can concussion of atoms beget..powers and energies that we feel in our minds? 1783 in Phil. Trans. LXXIII. 160 Nature unquestionably abounds with numberless unthought-of energies, and modes of working. 1801 Southey Thalaba iii. xvi, There might his soul develope best Its strengthening energies. 1849 Ruskin Sev. Lamps vii. 184 A measure of license is necessary to exhibit the individual energies of things. 1861 May Const. Hist. (1863) I. i. 6 The troublesome energies of Parliament. |
5. Power not necessarily manifested in action; ability or capacity to produce an effect.
| 1677 Hale Prim. Orig. Man. i. i. 26 We find in so small a particle of a created Being this admirable energy. 1691 T. H[ale] Acc. New Invent. p. xxiii, Some vain Authors have essayed in print to give reasons for such energy of that Fish. a 1732 Atterbury Serm. IV. ix. (T.), Discoursing of the energy and power of church music. a 1862 Buckle Civiliz. (1869) III. v. 420 An occult principle, which he termed the Animal Power or Energy of the brain. 1887 Lowell Democr. 36 Institutions which could bear and breed such men as Lincoln and Emerson had surely some energy for good. |
6. a. Physics. The power of ‘doing work’ possessed at any instant by a body or system of bodies. First used by Young (with reference to sense 4) to denote what is now called
actual energy,
kinetic energy, or
motive energy,
i.e. the power of doing work possessed by a moving body by virtue of its motion. (Young expressed the quantity of ‘energy’ in a particle as the product of the mass into the square of the velocity; it is now found more convenient to express it as the
half of this product.) Now extended (first by Rankine) to include
potential energy,
static energy, or
latent energy, or
energy of position,
i.e. the power of doing work possessed by a body in virtue of the stresses which result from its position relatively to other bodies. Also with
adjs.,
mechanical energy,
molecular energy,
chemical energy,
electrical energy, etc.;
atomic energy, see
atomic a. 2 d;
radiant energy (see
quots. 1901, 1942).
conservation of energy: the doctrine that the quantity of energy in any system of bodies cannot be increased or diminished by any mutual action of those bodies, and that the total energy in the universe is a constant quantity.
| 1807 T. Young Nat. Philos. viii. (1845) I. 59 The term energy may be applied, with great propriety, to the product of the mass or weight of a body, into the square of the number expressing its velocity. 1852 Thomson in Philos. Mag. 304 (title), Dissipation of Mechanical Energy. 1853 W. Rankine Transform. Energy in Scient. Papers (1881) 203 [Defines ‘actual or sensible energy’, ‘potential or latent energy’, ‘conservation of energy’]. 1863 Tyndall Heat i. §9 Asserting that mechanical energy may be converted into heat. 1876 M. Foster Physiol. ii. v. (1879) 420 The animal body is a machine for converting potential into actual energy. 1878 Huxley Physiogr. 199 But whether this is the sole source of volcanic energy or not is uncertain. 1879 Thomson & Tait Nat. Phil. I. i. §278 In every case in which energy is lost by resistance, heat is generated. 1901 S. Newcomb in J. M. Baldwin Dict. Philos. I. 326/1 Radiant energy or radiance. Every hot body radiates its heat through the space around it, thus imparting energy to the ether. The energy..is now believed to take a form of waves of electric energy..and its amount is exactly equal to that which the hot body loses. 1936 Nature 25 Jan. 135/1 Mass and energy are equivalent, and mass is to be regarded in a sense as a concentrated source of energy. 1942 J. D. Stranathan Particles ix. 374 Although sufficient quantitative evidence has already been presented..to convince one of the interchangeability of mass and energy..when an electron and a positron combine the two masses disappear and there appears simultaneously a definite amount of radiant energy. 1956 G. Thomson Atom (ed. 5) xvi. 156 It is one of the consequences of the theory of relativity that mass and energy are closely connected, so closely that when one appears the other must disappear. Ibid. 161 Uranium..splits into two nuclei..with a diminution of mass and consequent release of energy. |
† b. Suggested as a name for
momentum.
| 1808 Edin. Rev. XII. 130 This modification of power [that of a moving body, ‘proportional to the quantity of matter multiplied into the velocity’] might be called Energy. |
c. Veget.
Phys. energy of growth: see
quot.| 1882 Vines Sachs' Bot. 821 If the power of any particular zone to attain a definite length is called its Energy of Growth. |
d. (mental) energy (see
quots.).
| 1901 S. Newcomb in J. M. Baldwin Dict. Philos. I. 326/2 It is sometimes supposed that thought or mental action..may be a distinct form of energy... But the energy itself can be only that of the matter comprising the brain and nervous system. 1944 J. S. Huxley On Living in Rev. xv. 192, I shall use the term mental energy in the broad popular sense, as denoting the driving forces of the psyche, emotional as well as intellectual. |
7. attrib. and
Comb., as
energy-change,
energy consumption,
energy-density,
energy-exchange,
energy-level,
energy-producer,
energy-production,
energy-state,
energy unit,
energy value;
energy-carrying,
energy-giving,
energy-producing,
energy-rich adjs.| 1905 Westm. Gaz. 28 Apr. 2/1 The energy-carrying power of a beam of light. |
| 1884 M. M. P. Muir Princ. Chem. ii. iii. 453 The energy-changes attending the formation of various compounds. |
| 1909 Installation News III. 109/1 The energy consumption should not be below 500 watts. |
| 1958 H. J. Gray Dict. Physics 175/2 Energy density, amount of (e.g. radiant) energy in unit volume. |
| 1910 W. James Let. 17 June (1920) II. 345 Physically a dinosaur's brain may show as much intensity of energy-exchange as a man's. |
| 1941 J. S. Huxley Uniqueness of Man iii. iv. 96 The fertilizing, energy-giving belt of cyclonic weather. 1951 Good Housek. Home Encycl. 374/2 Energy-giving food. |
| 1910 W. James Let. 17 June (1920) II. 345 Certain arrangements of matter on the same energy-level are, from the point of view of man's appreciation, superior, while others are inferior. 1922 A. D. Udden tr. Bohr's Theory of Spectra iii. iv. 116 The values of the atomic energy corresponding to these states are frequently referred to as the ‘energy levels’ of the X-ray spectra. 1930 G. Thomson Atom xi. 164 The first outstanding fact in the theory of these extra nuclear electrons is the existence of what are called Energy Levels. The idea is that each electron in the atom requires an amount of energy to remove it completely from the atom, which is characteristic of the particular atom, and the particular electron, though more than one electron may be at the same energy level. |
| 1912 J. S. Huxley Individual in Animal Kingdom vi. 146 Some of the existing materials must be sacrificed as energy-producers. |
| 1909 Daily Chron. 8 July 6/4 An energy-producing food. |
| 1927 Haldane & Huxley Animal Biol. iii. 92 Children need a great deal more food per pound of their own weight for energy-production alone, besides their requirements for growth. 1952 New Biol. XIII. 125 The limited stock of abiotically formed energy-rich molecules. |
| 1955 W. Heisenberg in W. Pauli Niels Bohr 14 Schrödinger had recognized that the wave functions were the elements of the transformation matrices for the transition from energy states to position states. |
| 1948 Mind LVII. 299 We pay for our electric current in kilowatt-hours, which are energy units. |
| 1938 R. W. Lawson tr. Hevesy & Paneth's Man. Radioactivity (ed. 2) xi. 109 For the disruption of aluminium nuclei it is found that there are certain energy values (resonance levels) of the incident α-particles. |
b. Special
Comb.:
energy crisis,
crunch, a serious shortage of energy-producing fuels;
energy-efficient a. orig. U.S., that makes economical use of available energy,
esp. fuel; conducive to fuel economy; also
energy efficiency;
energy gap, (
a)
Physics, a gap between adjacent energy bands, such that a particle cannot pass from the lower to the higher without some minimum increase in its energy;
esp. that between the valence band and the conduction band in an insulator or semiconductor; (
b)
= energy crisis above.
| 1970 Sci. News 28 Nov. 415/1 The current short-term *energy crisis. 1971 Washington Post 10 Jan. f8/1 Although some progress has been made in dealing with the U.S. ‘energy crisis’, the likelihood of..blackouts in the coming year is not being ruled out. 1985 G. T. Nurse et al. Peoples of S. Afr. x. 250 Recurrent energy crises are endemic in African agricultural societies. |
| 1974 News & Press (Darlington, S. Carolina) 25 Apr. 8/7 There is..a distinct change of pattern in the automotive industry that was brought about by the *energy crunch. 1978 N.Y. Times Mag. 4 June 110 (heading) The real meaning of the energy crunch. |
| 1972 H. Perry Conservation of Energy 2 The principal theme of this report is that energy conservation and *energy efficiency are important issues. 1977 Sci. Amer. Dec. 47/3 The specification, which is called the energy efficiency ratio..is the quantity of heat energy (in British thermal units) removed from the air per hour divided by the electric power (in watts) supplied to the machine. 1986 Options Aug. 33/1 Energy efficiency is not..a subject on which the British can talk with much authority. |
| 1972 H. Perry Conservation of Energy ii. 50 As energy prices rise..a shift toward more *energy-efficient methods of moving people and freight can be expected to occur. 1975 Economist 27 Sept. 71/2 The car..must be made less polluting and more energy efficient. 1984 Today in Gainesville (Florida) Mar. 3a These homes are equipped with..energy-efficient insulation. |
| 1937 Seitz & Johnson in Jrnl. Applied Physics viii. 190/1 The conductivity σ..depends on E, the *energy gap between the filled and unfilled bands. 1954 F. London Superfluids II. 53 Various attempts have been made to modify the energy spectrum of the ideal Bose-Einstein gas in such a way as to fit the thermal data of liquid helium. The conclusion..is that something as drastic as an energy gap is required. 1959 R. A. Smith Semiconductors i. 16 If the forbidden energy gap ΔE between the highest filled band and the next empty band is large, no electronic conduction can take place as no ‘neighbouring’ empty levels exist into which electrons may be accelerated. 1969 East Europe Apr. 19/1 Recent economic difficulties in some communist countries can be linked to a developing energy gap, that is, the difference between their domestic energy resources at competitive prices and total energy requirements. 1977 Undercurrents June–July 8/1 Although North Sea oil and gas will make energy growth in Britain feasible during the 1980s, by the 1990s these reserves will be running out and we'll be faced with an ‘energy gap’. 1978 H. M. Rosenberg Solid State (ed. 2) viii. 131 If the energy gap is not too large, say 1 eV or less, a few electrons can be excited across the gap at room temperature and so a small current can flow... This is the behaviour typical of a semiconductor. 1985 Electronics 8 July 20/1 The energy gap for pyrite is 0.9 eV, which compares with 1.1 eV for silicon. |
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Add:
[7.] [b.] energy band, a set of permissible energy levels (for an electron in a solid) forming a continuous range or containing no significant energy gaps.
| 1937 Jrnl. Appl. Physics VIII. 191/2 Equilibrium results at a spacing at which the *energy bands are very narrow. 1984 D. C. Giancoli Gen. Physics xli. 813 The energy bands in semiconductors play an important role for transistors and diodes. |
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energy audit n. an assessment of energy provision, consumption, and efficiency,
esp. within a business or building;
cf. environmental audit n. at
environmental adj. Additions.
| 1936 C. Croneis & W. C. Krumbein Down to Earth p. iv, [Chapter] 4. *Energy audit, in which we examine the Earth's sources of energy, and follow this energy through the economy of our terrestrial globe. 1974 Science 19 Apr. 288, I sent out 45,000 letters to industry all over the country asking them to conduct individual energy audits for their companies. 1983 Which? Sept. 417/3 To save you doing the sums yourself to work out what insulation will prove worthwhile, you could consider getting an energy audit. 2000 Jrnl. (Salina) 4 Nov. d2/1 They're lobbying for the Endangered Species Act, conducting energy audits and educating others about global climate change. |
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energy drink n. orig. U.S. any of various types of drink which are considered a source of energy; (now)
esp. a soft drink containing a high percentage of sugar, or caffeine or another stimulant, typically consumed when participating in sports or as a means of overcoming tiredness;
cf. sports drink n. at
sport n.1 Compounds 4b.
| 1904 Cedar Rapids (Iowa) Gaz. 2 Apr. 5 (advt.) Vimalt. The great health tonic. An *energy drink. 1928 Chron.-Telegram (Elyria, Ohio) 17 Feb. 4 (advt.) Milk is the energy drink for youngsters. 1985 N.Y. Times 2 June f12/3 ‘Energy’ drinks such as Quaker Oats's Gatorade and Coca-Cola's MAX. 2001 B. Geddes World Food: Caribbean Gloss. 244/2 Guarana, high in caffeine, this nut was used by the Amerindians for medicinal purposes. It is now used in many energy drinks. 2006 CBS News Transcripts (Nexis) 20 June Energy drinks, those beverages that get their punch from caffeine and other stimulants. They're very popular with athletes, as well as..students pulling all-nighters. |
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energy bar n. orig. U.S. a pre-packaged food, similar in size and shape to a chocolate bar, which has a high calorie content and is considered a convenient source of energy.
| 1967 Argus (Fremont, Calif.) (Electronic text) 21 Feb. Someday these flights will be so fast we'll only have time to pass out ‘*energy bars’. 1990 Newsday (Nexis) 23 June ii. 7 If you exercise for more than 90 minutes, a snack will enhance your endurance... The commercial energy bars get the job done. 2000 Two Twenty Oct. 30/4 Do you really need the calorific intake from energy bars and drinks? If you don't use up the calories you'll end up a lard arse. |