▪ I. ‖ locus, n.1
(ˈləʊkəs)
Pl. loci (ˈləʊsaɪ).
[L. = place.]
1. a. Place in which something is situated, locality.
| 1715 Cheyne Philos. Princ. Relig. ii. 118 Yet Space is not actually to be divided; or one part of it separated from another. Since it is the universal Locus of, and penetrates all Bodies. 1874 Raymond Statist. Mines & Mining 516 These certificates were..entirely inadequate to determine the locus of the claims without parol testimony. 1876 Geo. Eliot Dan. Der. v. xxxix, We all of us carry on our thinking in some habitual locus where there is a presence of other souls. 1889 Syd. Soc. Lex., Locus, the whole space in or on which a thing is situated; a place. 1899 Allbutt's Syst. Med. VII. 395 It is even uncertain how far the writing-centre has a locus apart from the region in which impressions..are registered. 1901 Dundee Advertiser 10 Jan. 4 In Dundee the fish trade is divided against itself on a miserable question of the locus of its market. |
b. Genetics. A site or position on a chromosome at which a particular gene is located; loosely, a gene.
| 1913 Jrnl. Exper. Zoöl. XV. 591 White and eosin are allelomorphic to each other, that is, they occupy the same locus in the sex chromosome. 1915 T. H. Morgan et al. Mechanism Mendelian Heredity ii. 37 There are three pink eye colors in Drosophila, one whose locus is in the third chromosome (pink). Ibid. vii. 155 A mutant factor is located at a definite point in a particular chromosome; its normal allelomorph is supposed to occupy a corresponding position (locus) in the homologous chromosome. 1919 Anatomical Rec. XV. 358 In another case of duplication the duplication piece contains only the locus for sable as far as known. 1949 [see allelomorph]. 1962 Lancet 6 Jan. 10/1 The colour-blind locus is thought to be about 10 units of crossing-over from the locus for hæmophilia and about 25 units from the locus for Duchenne's type of muscular dystrophy. 1970 Nature 25 July 342/1 Considerable numbers of gene loci are required to code for the primary structures of the immunoglobulin molecules made in any one organism. 1971 Ibid. 13 Aug. 498/1 Haemoglobin type in sheep is controlled by a pair of alleles at a single locus. |
c. locus of control (Psychol.) (see quot. 19721).
| 1966 Mandler & Watson in C. D. Spielberger Anxiety & Behavior 286 A locus of control scale has been developed which differentiates individuals according to the degree to which they appraise themselves or the environment to control the occurrence of reinforcement. 1971 Jrnl. Gen. Psychol. LXXXV. 98 There is movement from external to internal locus of control from trial to trial. 1972 I. G. Sarason Personality (rev. ed.) i. 9 Locus of control refers to the degree to which an individual sees himself in control of his life and the events that influence it. 1972 Jrnl. Social Psychol. LXXXVI. 233 The work of Rotter and his associates on perceived locus of control has resulted in a considerable body of evidence. |
2. A subject, head, topic. [So in the Latin rhetorical writers, after Gr. τόπος.]
| 1753 Chambers Cycl. Supp. s.v. 1894 Bruce St. Paul's Concept. Chr. vii. 155 This manner of handling the locus of justification is very open to criticism. |
3. Math. The curve or other figure constituted by all the points which satisfy a particular equation of relation between coordinates, or generated by a point, line, or surface moving in accordance with any mathematically defined conditions.
| 1727–41 Chambers Cycl. s.v., A locus is a line, any point of which may equally solve an indeterminate problem. Ibid., All loci of the second degree are conic sections. 1758 Lyons Fluxions iv. §99 The locus of a simple equation is always a right line. 1848 Salmon Conic Sect. ii. §15 A single equation between the coordinates denotes a geometrical locus. 1879 Clifford Seeing & Thinking iv. (1880) 141 When a point moves along a line, that line is the locus of the successive positions of the moving point. 1881 Nature XXV. 131 The locus of the centre of this extraordinary barometric depression. 1885 C. Leudesdorf Cremona's Proj. Geom. 119 If two (non-concentric) pencils lying in the same plane are projective with one another (but not in perspective), the locus of the points of intersection of pairs of corresponding rays is a conic passing through the centres of the two pencils. |
4. In Latin phrases: locus classicus, a standard passage (esp. one in an ancient author) which is viewed as the principal authority on a subject; locus communis, a commonplace; locus desperatus (see quot. 1966); locus in quo, lit. ‘the place in which’ (something takes place), the locality of an event, etc.; in Law, used to designate the land on which trespass has been committed; locus pœnitentiæ (after Heb. xii. 17), a place of repentance; in Law, an opportunity allowed by law to a person to recede from some engagement, so long as some particular step has not been taken; locus standi, lit. ‘place of standing’; recognized position; in Law, a right to appear in court. Also genius loci (see genius 7).
| 1853 Bagehot Coll. Works (1965) I. 202 These lines are, as it were, the *locus classicus of fairy literature. 1864 H. Hayman Ex. Gk. & Lat. Verse Introd. p. xxii, If a special subject has a locus classicus, as chariot-racing..in the Electra of Sophocles. 1883 Sat. Rev. 7 Apr. 446/1 The inclusion of honourable traffic..[was] grounded upon an utter misconception of the three loci classici in the Mosaic law. 1885 Law Times LXXIX. 328/1 His action was successful, and the report of it is now a locus classicus in the law of life insurance. |
| 1531 Elyot Gov. i. xiv, Hauyng almoste all the places wherof they shal fetche their raisons, called of Oratours *loci communes, which I omitte to name. 1843 Mill Logic II. v. ii. 339 *Loci communes of bad arguments on some particular subject. |
| 1922 F. Klaeber Beowulf 214 This passage remains..a ‘*locus desperatus’. 1966 A. J. Bliss Dict. Foreign Words & Phrases Current Eng. 231 Locus desperatus, a passage in a text transmitted by manuscript whose meaning is so corrupt as to be almost beyond conjecture. 1969 English Studies p. lxxv, The result is an editorial ‘locus desperatus’ which still to some extent defies repeated scrutiny and modern photographic aids. 1969 R. Renehan Greek Textual Crit. 2 The textual critic..must decide in each case whether the original reading..has been or can be recovered by modern conjecture or whether the passage is a locus desperatus. 1970 Anglia LXXXVIII. 367 Faced with such a locus desperatus, even a conscientious editor might decline to grapple afresh with the battered folio. |
| 1717 Salkeld King's Bench Rep. I. 94 The Plaintiff demurred, because here are two Places alledged and the Avowant has only answered to the *locus in quo, &c. which is but one of the two Places. 1842 De Morgan in Graves Life Sir W. R. Hamilton (1889) III. 248 Is there anything else which I ought to look at of yours on the same subject? if so, will you oblige me with a reference to the locus in quo. 1892 Atkins Kelt or Gael i. 10 [They] suggest that the Aryan was a native of some cold part of Western Europe—Southern Scandinavia seems the latest favourite locus in quo. |
| a 1768 Erskine Instit. iii. ii. (1773) 427 The right competent to a party to resile from a bargain concerning land, before he has bound himself by writing is called in our law *locus pœnitentiæ. 1789 Term Rep. III. 149 An auction is not unaptly called locus penitentiæ. 1855 Newsp. Reader's Pocket Comp. i. 68 ‘The doors of the institution are open to a limited number of adult male criminals, as a locus poenitentiae’: that is to say, as a place for repentance and reformation. 1885 Sir J. Pearson in Law Rep. 29 Chanc. Div. 489, I see no locus pœnitentiæ given to him after he has once made his election. |
| 1835 J. W. Croker Ess. Fr. Rev. vi. (1857) 342 By this daring step Robespierre acquired a kind of *locus standi. 1886 Law Times LXXXII. 94/2 An expectant occupier has a locus standi to apply for the renewal of a public-house licence. 1911 J. Ward Realm of Ends x. 212 Death..means that the soul in consequence, so far as it is thus deprived of its locus standi, is..in the position of a deserter from the general order. 1974 Times 9 Feb. 20 The power of the Department [of Trade and Industry] should, of course, be discretionary but the Panel should be given a locus standi with the Department. |
Add: [4.] locus coeruleus (also caeruleus, ceruleus) Anat. [mod.L. locus caeruleus (J. & C. Wenzel De Penitiori Structura Cerebri (1812) xvii. 168)], a bluish-grey area on the floor of the fourth ventricle of the brain.
| 1858 Gray Anat. 472 Opposite the crus cerebelli, on the outer side of the fasciculi teretes, is a small eminence of dark grey substance, which presents a blueish tint through the thin stratum covering it; this is called the *locus cœruleus. 1874 Dunglison Dict. Med. Sci. (new ed.) 607/1 Locus caeruleus, a small eminence of dark gray substance, opposite the crus cerebelli, which presents a bluish tint through the thin stratum covering it. 1957 E. G. Walsh Physiol. Nervous Syst. xii. 458 One anatomical point is worth considering at this point, the extremely rich blood supply to the hypothalamus... The supraoptic nucleus is the most vascular region, but the paraventricular nucleus also is richly supplied with blood, as is also the locus caeruleus in the brain stem. 1972 Exper. Neurol. XXXV. 1 (heading) Nuclear size variations in cells of the locus ceruleus during sleep, arousal and stress. 1987 Daily Tel. 22 Apr. 5/2 The changes in the brain after 40 are seen in the locus coeruleus, a tiny area in the brain-stem that is a key centre for anxiety and fear. |
▪ II. locus, n.2 slang.
(ˈləʊkəs)
Also locust.
[As the earliest use is West Indian, the source may be Sp. loco lunatic (pl. locos): cf. loco n.1]
Something stupefying. Also attrib. in locus-ale, an intoxicating drink made of the scum of the sugar cane.
| 1693 Sir T. P. Blount Nat. Hist. 146 The first of which [viz. scum of sugar-cane] that ariseth is little worth; but afterwards, what is scumm'd off, they make a very good drink of, called Locus-Ale, much used by the Servants in Jamaica. 1851–61 Mayhew Lond. Labour III. 387 Some of the convicts would have given me some lush with a locust in it (laudanum hocussing). |
▪ III. locus, v. slang.
(ˈləʊkəs)
[f. locus n.2]
trans. To stupefy with drink. to locus away: to get away under the influence of drink. Cf. hocus v.
| 1831 Examiner 764/2 May threw a glass of the gin into Bishop's tea, when the latter said, ‘are you going to locus or Burke me?’ Mr. Horner explained that ‘locus’ was a cant word to describe the act of putting a man in a state of stupidity. [The report of the same case in John Bull 5 Dec. 386/3 has: ‘Are you going to hocus (or burk) me’.] 1868 Temple Bar XXIV. 539 ‘Locusing’ is putting a chap to sleep with chloroform and ‘bellowsing’ is putting his light out. 1898 J. A. Barry S. Brown's Bunyip, etc. 30 I've been shanghaied an' locussed away to sea, an' I wants to git back home again. |