embryo vs embryonal

embryo is a noun but embryonal is not a noun.

Word	Noun	Adjective	Verb	Adverb
embryo	Yes	No	No	No
embryonal	No	Yes	No	No

embryo (noun)	embryonal (noun)
an animal organism in the early stages of growth and differentiation that in higher forms merge into fetal stages but in lower forms terminate in commencement of larval life
(botany) a minute rudimentary plant contained within a seed or an archegonium

embryo (adjective)	embryonal (adjective)
	of an organism prior to birth or hatching