[a. F. aptitude (16th c. in Littré), ad. med.L. aptitūdo, n. of quality f. L. aptus: see APT a. and -TUDE. Cf. also ATTITUDE.]
1. The quality of being fit for a purpose or position, or suited to general requirements; fitness, suitableness, appropriateness.
1643. Milton, Divorce, I. iv. (1847), 128/2. That sociable and helpful aptitude … between man and woman.
1654. Warren, Unbelievers, 62. They lose their aptitude for heaven.
1749. [J. Mason], Power Pros. Numbers, 19. We are obliged for the Sake of Aptitude of Expression to make Use of Words that introduce the weak and feeble Numbers.
1809. Pinkney, Trav. France, 144. Its aptitude for the residence of a foreigner.
1851. Helps, Comp. Solitude, xi. (1874), 188. In any comparison so frequently used there must be some aptitude.
2. Natural tendency, propensity or disposition.
1633. Earl Manch., Al Mondo (1636), 90. Nor hath [the bodie] aptitude in it selfe to reanimation.
1693. Locke, Educ., § 66 (J.). He therefore, that is about Children, should well study their Natures and Aptitudes.
1859. Owen, Class. Mamm., 34. The aptitude of the Cheiroptera … to fall like Reptiles into a state of true torpidity.
3. Natural capacity, endowment or ability; talent for any pursuit.
1789–96. Morse, Amer. Geog., I. 257. A remarkable aptitude for mechanical inventions.
1855. Bain, Senses & Intell., II. i. § 23. Our estimate of time is one of the earliest of our mental aptitudes.
1879. Calderwood, Mind & Br., ix. 263. There is a physical acquisition, resulting in physical aptitudes.
b. transf. of countries: Capability, qualification.
1775. Burke, Concil. Amer., Wks. III. 123. If ever there was a country qualified to produce wealth, it is India…. America has none of these aptitudes.
1878. Bosw. Smith, Carthage, 47. The colonising and commercial aptitudes of Tyre.
c. esp. Natural capacity to learn or understand; intelligence, quick-wittedness, readiness.
1548. Udall, Erasm. Par., Pref. 14. Thy state of knowledge and aptitude or capacitie.
1838. Dickens, Nich. Nick., xxv. 205. The general idea … he had acquired with great aptitude.
