[1] : The Collaborative International Dictionary of English v.0.48

mammy \mam"my\ ma^m"my^, n.; pl. mammies
   ma^m"mi^z.
   a child's name for mamma, mother.
   1913 webster
see also:
mammies 

[2] : WordNet (r) 2.0

mammy
     n 1: an offensive term for a black nursemaid in the southern u.s.
     2: informal terms for a mother syn: ma, mama, mamma, mom,
         momma, mommy, mum, mummy, mater
see also:
ma mama mamma mom momma mommy 
mum mummy mater 

[3] : Moby Thesaurus II by Grady Ward, 1.0

27 moby thesaurus words for "mammy":
   amah, ayah, dam, dry nurse, foster mother, genetrix, ma, mam, mama,
   mater, materfamilias, maternal ancestor, matriarch, mom, mommy,
   mother, mummy, nanny, nurse, nursemaid, nurserymaid, old lady,
   old woman, sitter, stepmother, the old woman, wet nurse

Mammy >> M Words
Mammy, definition of term: Mammy
mammy_pag1.html