Difference between Mamma and Mammy

MAMMA vs MAMMY: NOUN

Informal terms for a mother
See mama.
Pl. mammæ (-ē). The mammary gland and associated structures; the characteristic organ of the class Mammalia, which in the female secretes milk for the nourishment of the young; a breast or udder.
[capitalized] A genus of sea-snails of the family Naticidæ.
A glandular organ for secreting milk, characteristic of all mammals, but usually rudimentary in the male; a mammary gland; a breast; udder; bag.
Mother; -- word of tenderness and familiarity.
Alternative spelling of mama: mother.
The milk-secreting organ of female humans and other mammals which includes the mammary gland and the nipple or teat; a breast; an udder. (plural: mammae)
An accessory cloud like a mammary in appearance, which can form on the underside of most cloud genera
Milk-secreting organ of female mammals

Informal terms for a mother
Mother.
A black nursemaid, especially one formerly in the southern United States.
Mother; mama: a childish word.
Hence In the southern United States, especially during the existence of slavery, a colored female nurse; a colored woman having the care of white children, who often continue to call her mammy after they are grown up.
Same as stone-lugger, 2.
A child's name for mamma, mother.
Mamma; mother
In the southern United States, a black nanny employed to look after white children.
An offensive term for a Black nursemaid in the southern U.S.

Moms, Mother, Mam, Ammi, Maman, Mammary gland, Mater, Mummy, Mum, Ma, Mammy, Mom, Mommy, Momma, Mama

Life, Mother, Ammi, Maman, Granny, Mam, Mummy, Mater, Mum, Mom, Ma, Mommy, Momma, Mama, Mamma

Daddy, Breast, Motherhood, Mother, Mam, Ammi, Maman, Mammary gland, Mummy, Mum, Mammy, Mom, Mommy, Momma, Mama

Grandma, Auntie, Life, Mother, Ammi, Maman, Granny, Mam, Mummy, Mum, Mom, Mommy, Momma, Mama, Mamma