spermatozoan vs gamete

spermatozoan and gamete both are nouns.

Word	Noun	Adjective	Verb	Adverb
spermatozoan	Yes	No	No	No
gamete	Yes	No	No	No

As nouns, gamete is a hypernym of spermatozoan; that is, gamete is a word with a broader meaning than spermatozoan:

spermatozoan: the male reproductive cell; the male gamete
gamete: a mature sexual reproductive cell having a single set of unpaired chromosomes

spermatozoan (noun)	gamete (noun)
the male reproductive cell; the male gamete	a mature sexual reproductive cell having a single set of unpaired chromosomes