mamma vs mommy

mamma and mommy both are nouns.

Word	Noun	Adjective	Verb	Adverb
mamma	Yes	No	No	No
mommy	Yes	No	No	No

As nouns, mamma and mommy are synonyms defined as:

Other synonyms of mamma include ma, mama, mammy, mom, momma, mum, mumma, mummy.

mamma (noun)	mommy (noun)
milk-secreting organ of female mammals	informal terms for a mother
informal terms for a mother