- embryonic, embryonal - of or relating to an embryo; "the embryonic membrane"
- embryonic, embryologic, embryonal - of an organism prior to birth or hatching; "in the embryonic stage"; "embryologic development"
Antonym: mature (indirect, via immature)
- embryonic, embryotic - in an early stage of development; "the embryo government staffed by survivors of the massacre"; "an embryonic nation, not yet self-governing"
Antonyms: late, later (indirect, via early)