Note: Though the presumed participle aptus is well-attested in Latin, the simple verb apere is known only from the lexicographical comments of the Roman grammarian Sextus Pompeius Festus. Possibly related on phonetic grounds to apere are the verbs coepī, coepisse "to begin" (attested only in the perfect) and apīscor, apīscī "to seize hold of, grasp, obtain, secure." The Latin complex is conventionally linked with Sanskrit ā́pa and Avestan āpa "has reached," Sanskrit āpnóti "reaches, overtakes," and Hittite epzi "seizes, captures," and appanzi "(they) seize," from an alleged Indo-European verbal base *h₁ep- "seize" (with the perfects in Latin and Sanskrit the outcome of a reduplicated *h₁e-h₁(o)p-). However, if the primary meaning of the Latin verb is "join," which appears likely (cf. cōpula "bond, fastening," from *co-ap-ula; see couple entry 1), then apīscī and coepī appear semantically too distant (unless, in an inchoative and middle derivative the sense "join oneself to" led to "seize hold of, obtain"?). If apere/aptus is unrelated to apīscī and coepī, another possible point of relation would be Hittite hāpzi "joins, attaches," going back to Indo-European *h₂ep-. (This would also ease the difficulty of accounting for the vocalism a- in Latin, at least in apere if not in apīscī.)