Lexical Definition

‎υἱοθεσία‎ huiothesía (hwee-oth-es-ee'-ah) adoption (as son) ^G:N-F
from a presumed compound of ‎υἱός‎ and a derivative of ‎τίθημι‎

adoption (of children, of sons).

• the placing as a son, i.e. adoption (figuratively, Christian sonship in respect to God)

Abbott-Smith

*† υἱοθεσία, -ας, ἡ (cf. the cl. phrases, υἱὸν τίθεσθαι, θετὸς υἱός), freq. in Inscr. (v. Deiss., BS, 239), adoption of a son (or daughter); metaph., of God's relation established
(a) with Israel: Ro 9:4;
(b) with Christ­ians: Ro 8:15, Ga 4:5, Eph 1:5; of its consummation, Ro 8:23.†

Abbott-Smith References

Liddell-Scott-Jones

υἱοθεσία-θεσία, ἡ,

adoption as a son, [Refs 2nd c.BC+]; in a religious sense, πνεῦμα υἱοθεσίαθεσίας [NT]; frequently in Inscrr., in the phrase καθ᾽ υἱοθεσίαθεσίαν, [υἱοθεσίαθεσίας ποιεῖσθαι 3rd c.AD(?): Diogenes Laertius 4.53. ">Refs 2nd c.BC+]

_{LSJ Scripture Refs: Rom.8.15 ☩ Gal.4.5}