Lewis & Short

ădoptĭo, ōnis, f. [v. adoptatio],

  1. I. a taking or receiving of one in the place of a child (also of a grandchild, Dig. 1, 7, 10), an adopting, adoption (properly of one still under paternal authority, in patria potestate; on the contr., arrogatio referred to one who was already independent, homo sui juris. The former took place before the praetor or other magistrate and five witnesses, by a threefold mancipatio, i. e. sham sale; the latter could only be effected before the assembled people in the comitia curiata, Gell. 5, 19; Just. Inst. 1, 11; Dig. 1, 7. More used than adoptatio, q. v.): emancipare filium alicui in adoptionem, Cic. Fin. 1, 7: dare se alicui in adoptionem, Vell. 2, 8, 2; Suet. Tib. 2; cf. Liv. 45, 40: adscire aliquem per adoptionem, Tac. A. 1, 3; or, in adoptionem, id. H. 2, 1: inserere aliquem familiae per adoptionem, Suet. Claud. 39 fin.: adscitus adoptione in imperium et cognomentum, Tac. A. 11, 11: adoptio in Domitium festinatur, id. ib. 12, 25: adoptionem nuncupare, to make known, to announce, id. H. 1, 17: adoptio consularis, performed by a consul, Quint. prooem. 6, 13 Spald. al.
  2. II. Transf., of plants, the ingrafting, Plin. prooem. 1, 16.
    Of bees, the admittance to or reception in a new hive: ut tamquam novae prolis adoptione domicilia confirmentur, Col. 9, 13, 9.
    In eccl. Lat., in spiritual sense of adoption as children of God: adoptionem filiorum Dei, Vulg. Rom. 8, 23; ib. Gal. 4, 5; ib. Ephes. 1, 5.