adoptive

[uh-dop-tiv] /əˈdɒp tɪv/
adjective
1.
of or involving adoption.
2.
acquired or related by adoption:
an adoptive father or son.
3.
tending to adopt.
Origin
1400-50; < Latin adoptīvus; see adopt, -ive; replacing late Middle English adoptife < Middle French adoptif
Related forms
adoptively, adverb
unadoptive, adjective
unadoptively, adverb
Can be confused
adaptive, adoptive.
adopted, adoptive.
Usage note
Although adoptive in the sense “acquired or related by adoption” can refer to either parent or child in such a relationship, adoptive is customarily applied to the parent (her adoptive mother) and adopted to the child (their adopted son).
British Dictionary definitions for adoptive

adoptive

/əˈdɒptɪv/
adjective
1.
acquired or related by adoption: an adoptive father
2.
of or relating to adoption Compare adopted
Word Origin and History for adoptive
adj.

early 15c., from Middle French adoptif, from Latin adoptivus "pertaining to adoption," from stem of adoptere (see adopt).