[ad. L. callōsus (cf. F. calleux) hard-skinned, callous, f. callum (callus) hardened skin: see -OUS.]
1. (Chiefly Phys. & Zool.) Hardened, indurated: as parts of the skin exposed to constant pressure or friction, or the cicatrized surfaces of ulcers. Also applied to parts that are naturally hard.
1578. Banister, Hist. Man, I. 4 b. With gowmes, which flesh is made so callous, and indurated.
1605. Timme, Quersit., III. 180. Callous and hollow ulcers.
1649. Jer. Taylor, Gt. Exemp., vi. § 7. The flesh of beasts grows callous by stripes and the pressure of the yoke.
1695. Congreve, Love for L., IV. xv. With labouring callous hands.
1797. Bewick, Brit. Birds (1847), I. 337. A callous conical protuberance.
1875. Jowett, Plato (ed. 2), I. 134. Hard and callous skins under their feet.
b. Bot.
1794. Martyn, Rousseau’s Bot., xvi. 180. The tips of the leaves being callous.
1884. Bower & Scott, Phaner. & Ferns, 174. The condition termed by Hanstein callous … consists in the thickening of the bands of membrane in all directions.
2. fig. Of the mind, feelings, conscience, etc., and of persons: Hardened, unfeeling, insensible.
1679. Goodman, Penitent Pardoned, I. iv. (1713), 109. The frequent injuries done to it [conscience] render it callous and insensible.
1729. Butler, Serm., Wks. 1874, II. 85. Totally hard and callous to impressions of religion.
1776. Hume, My own Life, 18 April, in Hist. Eng. (1825), Introd. 4. Callous against the impressions of public folly.
1833. Arnold, Lett., in Life & Corr. (1844), I. vii. 343. It is an immense blessing to be perfectly callous to ridicule.
1844. Disraeli, Coningsby, I. ix. 35. The callous bustle of fashionable saloons.
