Antonyms of adj biological

1 of 2 senses of biological

Sense 2
biological (vs. adoptive) -- (of parents and children; related by blood; "biological child")

adoptive (vs. biological) -- (of parents and children; related by adoption; "adoptive parents")
        => foster, surrogate -- (providing or receiving nurture or parental care though not related by blood or legal ties; "foster parent"; "foster child"; "foster home"; "surrogate father")

Similarity of adj biological

2 senses of biological

Sense 1
biological, biologic -- (pertaining to biology or to life and living things)

Sense 2
biological (vs. adoptive) -- (of parents and children; related by blood; "biological child")
       => begotten -- ((of offspring) generated by procreation; "naturally begotten child")
       => natural -- (related by blood; not adopted)