gonad vs ovotestis

gonad and ovotestis both are nouns.

Word	Noun	Adjective	Verb	Adverb
gonad	Yes	No	No	No
ovotestis	Yes	No	No	No

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

gonad: a gland in which gametes (sex cells) are produced
ovotestis: hermaphroditic gonad that contains both testicular and ovarian tissue

Other hyponyms of gonad include ovary, ball, ballock, bollock, egg, nut, orchis, testicle, testis.

gonad (noun)	ovotestis (noun)
a gland in which gametes (sex cells) are produced	hermaphroditic gonad that contains both testicular and ovarian tissue