perturb, v.
(pəˈtɜːb)
[a. OF. per-, partourber, -turber (14th c. in Godef.), ad. L. perturbare, f. per- 2 + turbāre to disturb, confuse.]
1. a. trans. To disturb greatly (physically or externally); to cause disorder or irregularity in; to unsettle, confuse, derange, throw into confusion.
| c 1386 Chaucer Knt.'s T. 48 What folk been ye that at myn hom comynge Perturben [v. rr. perturbe, -tourbe(n; Camb. MS. disturblen] so my feste with criynge. 1490 Caxton Eneydos i. 13 The force and strengthe of the troyians was thenne so perturbed by the pryckynge of fortune. 1568 Grafton Chron. II. 69 Notyng in him arrogancy and wilfulnesse, in perturbyng and refusyng such an honest order of agreement. 1599 Jas. I βασιλ. Δωρον To Rdr., Rash-headed Preachers, that thinke it their honour to contend with kinges and perturbe whole kingdomes. 1646 Sir T. Browne Pseud. Ep. vi. vi. 295 Perturbing the Chaldean and ægyptian Records with fabulous additions. 1874 Morley Compromise iii. 96 To perturb the pacific order of society either by active agitation or speculative restlessness. |
b. Astron. (
Cf. perturbation 2 b.)
| 1879 Proctor Pleas. Ways Sc. iii. 68 The members of the sun's family perturb each other's motions in a degree corresponding with their relative mass. Ibid. 69 The earth plays..but a small part in perturbing the planetary system. |
2. To disturb greatly (mentally), to trouble; to disquiet, agitate, discompose.
| c 1374 Chaucer Troylus iv. 533 (561) Ȝit drede I moste hire herte to perturbe With vyolence ȝif I do swych a game. c 1430 Lydg. Min. Poems (Percy Soc.) 16 No child be falce iniquité Purturbed never his felicité. 1552 Lyndesay Monarche 5094 Gretlye it doith perturbe my mynde. 1632 B. Jonson Magn. Lady i. i, I do neuer feel myself perturb'd With any general words 'gainst my profession. 1826 Scott Woodst. v, His childish imagination was perturbed at a phenomenon for which he could not account. |
| absol. c 1470 [see pertrouble]. 1558 T. Phaer æneid vi. R iij b, Thy greuous ghost, Perturbing in my dremes hath me compeld to see this coast. 1902 Daily Chron. 23 Apr. 3/3 It is the unexpected that perturbs. |
3. Physics and
Math. To subject (a physical system, or a set of equations, or its solution) to a perturbation (sense 4).
| 1901, etc. [implied in perturbed ppl. a. 2]. 1931 Physical Rev. XXXVIII. 875 The 3P20 sequence is perturbed by X3P20. 1973 Nature 17 Aug. 416/1 If the initial potential is that of a hard sphere, this can be ‘perturbed’ into a realistic form by adding an attractive term and softening the repulsion. |
Hence
perˈturbing vbl. n. and ppl. a.| c 1386 Chaucer Sompn. T. 546 Whan þat þe weder is fair With-outen wynd, or perturbynge of Air. 1647 Ward Simp. Cobler 46 Distracted Nature calls for distracting Remedies; perturbing policies for disturbing cures. 1796 W. Taylor in Monthly Mag. II. 464 A mean to conjure away this perturbing spirit. 1862 H. Spencer First Princ. ii. v. §56 (1875) 182 The maintenance of a circular orbit by any celestial body, implies..that there are no perturbing bodies. |