amphimixis vs anisogamy

amphimixis and anisogamy both are nouns.

Word	Noun	Adjective	Verb	Adverb
amphimixis	Yes	No	No	No
anisogamy	Yes	No	No	No

As nouns, anisogamy is a hyponym of amphimixis; that is, anisogamy is a word with a more specific, narrower meaning than amphimixis:

amphimixis: reproduction involving the union or fusion of a male and a female gamete
anisogamy: (biology) reproduction by the union or fusion of two differing gametes (especially differing in size)

Other hyponyms of amphimixis include isogamy.

amphimixis (noun)	anisogamy (noun)
union of sperm and egg in sexual reproduction	(biology) reproduction by the union or fusion of two differing gametes (especially differing in size)
reproduction involving the union or fusion of a male and a female gamete