▪ I. decay, n.
(dɪˈkeɪ)
For forms see the verb.
[f. decay v. Cf. med.L. decheium in Du Cange.]
1. a. The process of falling off from a prosperous or thriving condition; progressive decline; the condition of one who has thus fallen off or declined.
| c 1460 Fortescue Abs. & Lim. Mon. xvi, The estate off þe Romans..hath ffallen alwey sythyn, into suche decay, þat nowe [etc.]. 1558 Bp. Watson Sev. Sacram. i. 3 He repayreth all our decaies in grace. 1587 Mirr. Mag., Albanact lxvi, Discord brings all kingdomes to decay. 1611 Bible Lev. xxv. 35 If thy brother bee waxen poore, and fallen in decay with thee. 1718 Hickes & Nelson J. Kettlewell iii. §103. 439 Perceiving..a very Sensible Decay of his Spirits. 1856 Froude Hist. Eng. (1858) I. i. 9 At present, the decay of a town implies the decay of the trade of the town. 1874 Green Short Hist. v. §3. 228 The decay of the University of Paris..had transferred her intellectual supremacy to Oxford. |
† b. Formerly sometimes = Downfall, destruction, ruin; poet. fall, death. Obs.
| 1535 Coverdale Ps. cv[i]. 36 They worshipped their ymages, which turned to their owne decaye. 1590 Spenser F.Q. i. vi. 48 In hope to bring her to her last decay. Ibid. ii. ix. 12 Fly fast, and save yourselves from neare decay. 1593 Shakes. Lucr. 516 To kill thine honour with thy liues decaie. 1595 ― John iv. iii. 154. a 1724 Battle of Harlaw xxv. in Ramsay Evergreen, Grit Dolour was for his Decay, That sae unhappylie was slain. |
2. † a. Falling off (in quantity, volume, intensity, etc.); dwindling, decrease. Obs.
| 1636 Blunt Voy. Levant (1637) 46 The opinion of our decay in stature from our forefathers. 1662 Stillingfl. Orig. Sacr. iii. iv. §6 The decay of many of them [springs] in hot and dry weather. 1669 A. Browne Ars Pict. (1675) 39 The shadows..being caused by the decay of the light. 1691 T. H[ale] Acc. New Invent. p. lxxxiv, Complaints were brought to the Council-Board, of the great Decay of that River. 1816 J. Smith Panorama Sc. & Art II. 62 The decay of sound has been supposed by some to be nearly in the direct ratio of the distances. |
b. Physics. The gradual decrease in the radioactivity of a substance; hence, the spontaneous transformation of a single atomic nucleus or elementary particle into one or more different nuclei or particles. Also attrib.
| 1897 Rutherford in Phil. Mag. XLIV. 425 The intensity of the radiation varied widely, but in all cases the rate of decay was found to be in close agreement with theory. 1902 Rutherford & Allen in Phil. Mag. IV. 708 The decay-curve for a copper wire exposed 210 minutes inside the laboratory. 1905 Nature 13 Apr. 574/1 Different samples gave for the half-period of decay from 52 to 55 seconds. 1931 G. Gamow Constitution of Atomic Nuclei ii. 31 One of the most important characteristics of a decaying nucleus is its decay constant.., giving the probability of disintegration per unit time. 1938 R. W. Lawson tr. Hevesy & Paneth's Man. Radioactivity (ed. 2) xxiii. 223 Uranium Z..may be a decay product of a uranium isotope other than 238U. 1958 J. L. Perkin in O. R. Frisch Nucl. Handbk. iii. 7 The decay of a nucleus via various excited levels of the final nucleus is shown diagrammatically. 1962 H. D. Bush Atomic & Nuclear Physics iv. 81 The half-life of uranium I..is obviously too long to determine by measuring the decay of its activity. 1968 M. S. Livingston Particle Physics xi. 196 The most fundamental weak interaction is the decay of the neutron into a proton, an electron, and an antineutrino. 1969 Times 12 Mar. 4/7 The radioactive decay of uranium..has long been recognized as a means of fixing the ages of remote cosmological events. |
c. A progressive diminution in the amplitude of an oscillation or vibration.
| 1906 J. A. Fleming Princ. Electr. Wave Telegr. i. 15 Frictional resistance causes decay in the amplitude of the oscillations by dissipating their energy as heat. 1922 Glazebrook Dict. Appl. Physics II. 111/1 The damping of the oscillations is determined by b..which is called the damping coefficient or the coefficient of decay. 1950 Stephens & Bate Wave Motion & Sound 357 This decay of amplitude is known as damping and the motion is referred to as damped harmonic motion. 1962 A. Nisbett Technique Sound Studio iii. 56 Some percussive instruments, such as tympani, continue to sound for some time, and have decay characteristics which are somewhat similar to that of reverberation. |
3. a. Of material things: Wasting or wearing away, disintegration; dilapidation, ruinous condition.
| 1523 Fitzherb. Surv. 1 Those castelles..that be fallen in dekay and nat inhabyted. c 1600 Shakes. Sonn. xiii. 9 Who lets so fair a house fall to decay? 1756–7 tr. Keysler's Trav. (1760) II. 248 That edifice, by length of time, fell to decay, and lay in ruins. 1839 Keightley Hist. Eng. II. 41 The decay of these sacred edifices. |
† b. pl. Dilapidations; concr. ruined remains, ruins, debris, detritus. (Rarely in sing.) Obs.
| 1582 in W. H. Turner Select. Rec. Oxford 427 The Bayliffs..shall..make relation unto this howsse what the decayes are. 1615 G. Sandys Trav. 176 Beyond are the decayes of a Church. 1632 Lithgow Trav. v. 200 The decayes whereof being much semblable to..the stony heapes of Jericho. 1655 Fuller Ch. Hist. iii. vi. §26. 82 Jehoida was careful to amend the decayes of the Temple. 1777 G. Forster Voy. round World I. 313 A vegetable mould, mixed with volcanic decays. |
| fig. 1605 Shakes. Lear v. iii. 297 What comfort to this great decay may come Shall be appli'd. 1662 South Serm. I. ii. Gen. i. 27 And certainly that must needs have been very glorious the decayes of which are so admirable. |
c. fig. The gradual ‘wearing down’ of words or phonetic elements in language.
| 1874 Sayce Compar. Philol. i. 18 Contraction and decay may be carried so far as to become an idiosyncracy of a particular language. 1877 T. L. Papillon Man. Comp. Philology iv. 56 The principle of ‘Phonetic Decay’, which plays so large a part in the history of language. |
4. a. Decline of the vital energy or faculties (through disease or old age); breaking up of the health and constitution; formerly also (with pl.), effect, mark, or sign of physical decay.
| c 1600 Shakes. Sonn. xi, Age and could decay. 1611 B. Jonson Catiline ii. i, She has been a fine lady..and paints, and hides Her decays very well. 1720 Wodrow Corr. (1843) II. 498 Notwithstanding my great age and decays, I am able to preach..in the largest meeting-house in Boston. 1752 Johnson Rambler No. 203 ¶12 In the pains of disease, and the languor of decay. 1860 Hook Lives Abps. (1869) I. vii. 421 The archbishop..had begun to show symptoms of decay. |
† b. spec. Consumption, phthisis; ‘a decline’.
| 1725 N. Robinson Th. Physick 150 A perfect Hectic, which inseparably accompanies Wastes, Decays, and Consumptions. 1746 Berkeley Let. Tar-Water §23 Dropsies, decays, and other maladies. 1818 Scott Hrt. Midl. xviii, Her son that she had left at hame weak of a decay. |
5. The destructive decomposition or wasting of organic tissue; rotting.
| 1594 Plat Jewell-ho. ii. 42 One day, or two, before you feare the decay of your decoction, set the same on the fire. 1748 F. Smith Voy. I. 138 Such Wood as is upon the Decay, but not yet become rotten. 1771 J. Hunter Hist. Teeth 122 Fill the hole with lead, which prevents the pain and retards the decay. 1775 Harris Philos. Arrangem., The body ceases to live, and the members soon pass into putrefaction and decay. 1860 Ruskin Mod. Paint. V. viii. i. 159 The decay of leaves. 1878 L. P. Meredith Teeth 115 The teeth will come together, and further decay will almost infallibly result. |
† 6. A cause of decay; the ‘destruction’ or ‘ruin of’ anything. Obs.
| 1563 Homilies ii. x. Pt. i, Som worldly witted men think it a great decaye to the quiete and prudent gouernynge of their commonwealthes to geue eare to the simple and playne rules..of our Sauiour. 1584 D. Powel Lloyd's Cambria 21 This partition is the very decaie of great families. c 1600 Shakes. Sonn. lxxx, My loue was my decay. 1674 Wood Life (O.H.S) II. 300 The decay of study, and consequently of learning, are coffy houses. 1690 Child Disc. Trade (ed. 4) 235 Trade, to which the high rate of Usury is a great prejudice and decay. |
† 7. Failure of payment or rent; arrears. Obs. [med.L. decasus redditus, decatum.]
| 1546 in Eng. Gilds (1870) 199 The possessiones of the Guyld, wyth the decayes, ben yerly valued at [etc.]. Ibid., Decayes and defautes of Rentes. 1546 Mem. Ripon (Surtees) III. 31 One Annuall Rent..in decay and not payde. |
▪ II. decay, v.
(dɪˈkeɪ)
Forms: 5– decay; also 5–6 dekay(e, dekey, 6–7 decaye, -aie.
[a. OF. decair, dekair (subj. pres. decaie), var. of decaoir, dechaoir, decheoir, now déchoir = Sp. decaer, Pg. decahir, It. decadēre, a Com. Rom. compound of de- down + cadēre = L. cadĕre to fall. The F. forms in -eir, -oir correspond to the -ēre type, those in -ir in OF. and Pg. have passed over to the -īre conjugation.]
I. intr.
1. a. To fall off (in quality or condition); to deteriorate or become impaired; to lose its characteristic quality, strength, or excellence; to be in a failing condition.
| 1494 Fabyan Chron. v. xcv. 69 The seruyce of God..by mean of y⊇ Saxons was greatly decayde through all Brytayne. 1511–2 Act 3 Hen. VIII, c. 3 Preamb., Archerie..is right litell used, but dayly mynessheth, decayth and abateth. 1583 Stubbes Anat. Abus. ii. (1882) 73 Whereby learning greatlie decaieth. 1602 Rowlands Kind Gossips (1609) 18 His loue to me now daily doth decay. 1677 A. Yarranton Eng. Improv. 49 Common Honesty is necessary for Trade, and without it Trade will decay. 1728 Pope Dunc. i. 277 How Prologues into Prefaces decay. 1812 J. Wilson Isle of Palms iii. 273 Entranced there the Lovers gaze Till every human fear decays. |
b. To decline from prosperity or fortune.
| 1483 Act 1 Rich. III, c. 12 §1 The Artificers of this seid Realme..ben greatly empoveresshed and dailly dekeyn. 1483 Caxton Cato H ij, It is seen selde the juste to dekaye ne to haue nede. 1535 Coverdale Prov. xi. 11 When the iust are in wealth, the cite prospereth: but whan the vngodly haue the rule, it decayeth. 1663 Pepys Diary 15 May, The Dutch decay there [in the East Indies] exceedingly. 1816 Scott Old Mort. i, Ancient..families..decayed into the humble vale of life. |
2. † a. To fall off or decrease (in number, volume, amount, intensity, etc.); to dwindle away. Obs.
| 1489 Act 4 Hen. VII, c. 16 The which Isle is lately decayed of people. 1568 Bible (Bishops') Job xiv. 11 The fludde decayeth and dryeth vp. 1634 Sir T. Herbert Trav. 168 It became a hard question, whether my spirits or Gold decayed faster. 1691 T. H[ale] Acc. New Invent. p. xc, The Shipping and Number of our Seamen were decay'd about a third part. 1698 Fryer Acc. E. Ind. 67 The Water drank is usually Rain-water preserved in Tanks, which decaying, they are forced to dig Wells. 1725 Pope Odyss. xii. 237 Till, dying off, the distant sounds decay. c 1790 J. Imison Sch. Art. I. 126 The candle will burn a minute; and then, having gradually decayed from the first instant, will go out. |
b. Of an oscillation or vibration: gradually to decrease in amplitude, so that each swing is smaller than the one before. Also said of the amplitude of the oscillation.
| 1879 Encycl. Brit. VIII. 11/2 Sir W. Thomson investigated mathematically the discharge of a Leyden jar..and predicted that under certain circumstances the discharge would consist of a series of decaying oscillations. 1906 J. A. Fleming Princ. Electr. Wave Telegr. 573 A very important matter in connection with practical electric wave telegraphy is the rate at which the wave amplitude decays during the emission of a wave train from the antenna. 1927 I. B. Crandall Theory of Vibr. Syst. i. 8 The natural oscillations may be made to decay very rapidly, or to disappear altogether, if the damping factor is made very large. 1944 A. Wood Physics of Music ii. 23 Sound-waves are carrying energy more rapidly away from the fork, and the vibrations therefore decay more rapidly. 1959 Chambers's Encycl. I. 375/1 The amplitude of the swing about the final true position decays exponentially with time. |
c. Physics. Of radioactivity: gradually to diminish in intensity; of a substance: to suffer a gradual decrease in its radioactive power, to undergo nuclear disintegration. Hence, of a radioactive substance, an atomic nucleus, or an elementary particle: to change or disintegrate into one or more different substances, etc.
| 1900 Rutherford in Phil. Mag. XLIX. 177 The intensity of the ‘excited’ radiation falls to half its value in about eleven hours, or one decays 660 times faster than the other. 1913 ― Radioactive Substances viii. 339 The active deposit..decays in situ and this results in an apparent decrease of the activity. 1942 J. D. Stranathan ‘Particles’ Mod. Physics viii. 326 The half life period T of a radioactive substance is defined as the time required for one half of the active material present at any time to decay. 1958 W. K. Mansfield Elem. Nuclear Physics iii. 21 It is found experimentally that the probability of an unstable nucleus, known as a radioactive nucleus, decaying within a given time is constant. 1962 H. D. Bush Atomic & Nuclear Physics iv. 80 Uranium X does not decay into a stable product but is the parent of a chain of radioactive daughter products. 1968 M. S. Livingston Particle Physics iv. 72 In matter, when π+ pions are slowed down by ionizing impacts, they decay into positive muons and muon neutrinos. |
3. a. To fall into physical ruin; to waste away, wear out, become ruined.
| 1494 Fabyan Chron. iii. lvi. 36 Aruiragus..with great dilygence Repayred Cyties and Townes before decayed. 1570–6 Lambarde Peramb. Kent (1826) 283 This house, by that time..was decaied, either by age, or flame, or bothe. 1635 Milton On Hobson ii, Made of sphere metal, never to decay Until his revolution was at stay. 1694 Coll. Sev. Late Voy. (1711) I. 45 There was Water over the Salt, which began to decay with the Rain and Weather being on it. 1748 F. Smith Voy. I. 51 The Ise being inseparable, as it was very little decayed. |
b. To suffer decomposition; to rot.
| 1580 Baret Alv. D 178 That soone is ripe, doth soone decaie. 1737 Pope Hor. Epist. ii. ii. 319 As winter fruits grow mild ere they decay. 1771 J. Hunter Hist. Teeth 122 When an opening is made into the cavity of the Tooth, the inside begins to decay. 1851 Carpenter Man. Phys. (ed. 2) 22 The parent-cell having arrived at its full development..dies and decays. |
4. To fall off in vital energy; to lose health and strength (of body or faculties); also, to lose the bloom of youth and health.
| 1538 Starkey England i. ii. 48 Wythout the wych hys helth long can not be maynteynyd; but, schortly, of necesstye hyt must dekay. 1655 Culpepper Riverius i. xi. 38 His Imagination began to decay. 1712–14 Pope Rape Lock v. 25 But since, alas! frail beauty must decay. 1795 Southey Joan of Arc vii. 337 Feel life itself with that false hope decay. 1875 Jowett Plato (ed. 2) V. 20 An author whose original powers are beginning to decay. |
II. trans.
† 5. To cause to fall off or deteriorate. Obs.
| 1529 More Comf. agst. Trib. ii. Wks. 1200/2 For feare of decaying the common wele, men are driuen to put malefactors to pain. 1565 Jewel Def. Apol. (1611) 362 We haue decaied no mans Power or right. 1665 Manley Grotius' Low C. Warres 299 His last five years had much decayed his Reputation. 1691 Locke Lower. Interest Wks. 1727 II. 38 A High Interest decays Trade. |
† 6. To cause to fall off (in number, amount, etc.); to reduce, cause to dwindle. Obs.
| 1550 Crowley Epigr. 734 Yet can there nothynge My flocke more decaye, Then when hyrelynges suffer My shepe go astraye. 1600 Holland Livy i. xlix. 35 a, When he had decaied the number of the nobles. a 1626 Bacon Max. & Uses Com. Law iv. (1636) 23 If I do decay the game whereby there is no Deere. |
† 7. a. To waste or ruin physically; to disintegrate, dilapidate; to bring to decay or ruin. Obs.
| 1536 Exhort. North in Furniv. Ballads from MSS. I. 306 Downe streght to the grownde Many are besy them [abbeys] to dekay. 1605 Bacon Adv. Learn. i. viii. §6 (1873) 72 Palaces, temples, castles, cities, have been decayed and demolished. 1636 Sir H. Blount Voy. Levant (1637) 46 Where there were any raine, it would settle..and decay the building. 1703 Moxon Mech. Exerc. 239 No time will impair or decay those Grey Kentish Bricks. |
b. To destroy by decomposition; to rot.
| 1616 B. Jonson Divell an Asse iv. iii, [It] decayes the fore-teeth. 1626 Bacon Sylva §995 To lay that which you cut off to putrefie, to see whether it will decay the rest of the stock. 1703 T. N. City & C. Purchaser 210 Lime and Wood are insociable, the former very much corrodeing and decaying the latter. 1893 Mrs. A. Arnold in Westm. Gaz. 27 Feb. 9/2 Is it probable that a blooming girl would defile her breath, decay her teeth, and damage her complexion [by smoking]? |
8. To cause (the body or faculties) to fail in vital energy, health, or beauty.
| 1540–54 Croke Ps. (Percy Soc.) 24 Ther is no tyme can the decaye. 1568 E. Tilney Disc. Mariage C j b, Wine..if it be abused..decaying womens bewtie. a 1668 Denham Of Old Age 217 ‘But Age’, 'tis said, ‘will memory decay’. 1713 Addison Guardian No. 120 ¶7 Almost every thing which corrupts the soul decays the body. 1718 Lady M. W. Montagu Let. to C'tess of Mar 10 Mar., She had the remains of a fine face..more decayed by sorrow than time. |