instability
(ɪnstəˈbɪlɪtɪ)
[a. F. instabilité (15th c. in Hatz.-Darm.), ad. L. instabilitāt-em, f. instabilis instable.]
The quality of being unstable; lack of stability in regard to position, condition, or moral qualities; want of steadiness, fixity, or firmness of purpose or character. With an and pl., an instance of this.
| c 1422 Hoccleve Learn to Die 863 Fful fewe been, þat..Konne apparceyue thinstabilitee Of the world. 1548 Hall Chron., Hen. IV 15 Some lamentyng the instabilitee of the Englishe people, iudged theim to be spotted with perpetuall infamie. 1640–4 Earl of Bristol in Rushw. Hist. Coll. iii. (1692) I. 714 The Scripture telleth us of..the Instability of a Kingdom Divided within it self. 1646 Sir T. Browne Pseud. Ep. ii. vi. 96 Parallels or like relations..by their mutuall concurrences support their solitary instabilities. 1781 C. Johnstone Hist. J. Juniper II. 220, I had leisure to reflect on the instability of human happiness. 1783 Johnson Let. to Mrs. Thrale 21 Oct., Endeavour to reform that instability of attention which your last letter has happened to betray. 1856 Stanley Sinai & Pal. ii. (1858) 125 Nothing conveys..so strong a sense of general instability and insecurity as the recurrence of earthquake. 1878 Stewart & Tait Unseen Univ. vi. §178. 181 Molecular instability, such as water cooled below freezing point. |
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Add: b. spec. in Psychol. Tendency to unpredictable behaviour or erratic changes of mood. (Usu. with qualifying word.)
| 1897 Pop. Sci. Monthly July 390 Great mental instability marks the true mob. 1926 [see popularization n.]. 1952 O. Nash Let. 5 Nov. in L. N. Smith Loving Lett. (1990) 286, I am..sure you must realize how deeply concerned I am about [—]'s family history. Emotional instability, melancholia, depression, are material, practical, frightening things, and torture to live with. 1965 J. Pollitt Depression & its Treatment v. 71 The tendency to increased psychological instability in the premenstrual phase has been demonstrated by Dalton. 1983 Oxf. Textbk. Med. II. xxiv. 20/2 Depression, emotional instability, and quarrelsomeness accompany the lassitude and anorexia. |