teat vs mammilla

teat and mammilla both are nouns.

Word	Noun	Adjective	Verb	Adverb
teat	Yes	No	No	No
mammilla	Yes	No	No	No

As nouns, teat and mammilla are synonyms defined as:

Other synonyms of teat include mamilla, nipple, pap, tit.

teat (noun)	mammilla (noun)
the small projection of a mammary gland	the small projection of a mammary gland