Definition of "apter"

Thou tremblest; and the whiteness in thy cheekIs apter than thy tongue to tell thy errand.

c. 1596–1599 (date written), William Shakespeare, “The Second Part of Henry the Fourth, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene i]

[I]t hath been many an honest man's hap to pass for the father of children he never begot; and if your worship should provide for the child, it may make the people the apter to believe […]

1749, Henry Fielding, The History of Tom Jones, a Foundling

Would you deign to be my instructress, I should prove an apter scholar than if taught by Signor Rappaccini himself.

1844, Nathaniel Hawthorne, Rappaccini's Daughter