Ăpt’i-tūde, n.

(53), n. [Fr. aptitude, L. Lat. aptitudo. See APT.]

1. A natural or acquired disposition for a particular purpose, or tendency to a particular action or effect; as, oil has an aptitude to burn; men acquire an aptitude to particular vices.
2. A general fitness or suitableness.

That sociable and helpful aptitude which God implanted between man and woman. Milton. 3. Readiness in learning; docility; aptness. “He was a boy of remarkable aptitude.” Macaulay.