apt (adj.)

mid-14c., "inclined, disposed;" late 14c., "suited, fitted, adapted, possessing the necessary qualities for the purpose," from Old French ate "fitting, suitable, appropriate" (13c., Modern French apte), or directly from Latin aptus "fit, suited, proper, appropriate," adjectival use of past participle of *apere "to attach, join, tie to," from PIE root *ap- (1) "to grasp, take, reach" (source also of Sanskrit apnoti "he reaches," Latin apisci "to reach after, attain," Hittite epmi "I seize"). Elliptical sense of "becoming, appropriate" is from 1560s.