testicle vs sex gland

testicle and sex gland both are nouns.

Word	Noun	Adjective	Verb	Adverb
testicle	Yes	No	No	No
sex gland	Yes	No	No	No

As nouns, sex gland is a hypernym of testicle; that is, sex gland is a word with a broader meaning than testicle:

testicle: one of the two male reproductive glands that produce spermatozoa and secrete androgens
sex gland: a gland in which gametes (sex cells) are produced

Other hypernyms of testicle include gonad, male reproductive gland.

testicle (noun)	sex gland (noun)
one of the two male reproductive glands that produce spermatozoa and secrete androgens	a gland in which gametes (sex cells) are produced