mummy vs mumma

mummy and mumma both are nouns.

Word	Noun	Adjective	Verb	Adverb
mummy	Yes	No	No	No
mumma	Yes	No	No	No

As nouns, mummy and mumma are synonyms defined as:

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

mummy (noun)	mumma (noun)
a body embalmed and dried and wrapped for burial (as in ancient Egypt)	informal terms for a mother
informal terms for a mother