adoption (n.)

mid-14c., from Old French adopcion or directly from Late Latin adoptionem (nominative adoptio) "a taking as one's child," shorter form of adoptatio, noun of action from past participle stem of Latin adoptare "chose for oneself, take by choice, select, adopt," especially "to take into a family, adopt as a child," from ad "to" (see ad-) + optare "choose, wish, desire," from PIE root *op- (2) "to choose" (see option (n.)).