aptyoudaoicibaDictYouDict
apt: [14] Apt comes from Latin aptus ‘fit, suited’, the past participle of the verb apere ‘fasten’. Other English words from this source are adapt, adapt, adept, inept, and (with the Latin prefix com-) couple and copulation. Related words are found in Indo-European languages of the Indian subcontinent: for instance, Sanskrit āpta ‘fit’.
=> adapt, adept, attitude, couple, inept
apt (adj.)youdaoicibaDictYouDict
mid-14c., "inclined, disposed;" late 14c., "suited, fitted, adapted," from Old French ate (13c., Modern French apte), or directly from Latin aptus "fit, suited," adjectival use of past participle of *apere "to attach, join, tie to," from PIE root *ap- (1) "to grasp, take, reach" (cognates: Sanskrit apnoti "he reaches," Latin apisci "to reach after, attain," Hittite epmi "I seize"). Elliptical sense of "becoming, appropriate" is from 1560s.