Source : Webster's Revised Unabridged Dictionary (1913)

Mamma \Mam*ma"\, n. [Reduplicated from the infantine word ma,
   influenced in spelling by L. mamma.]
   Mother; -- word of tenderness and familiarity. [Written also
   {mama}.]

         Tell tales papa and mamma.               --Swift.

Mamma \Mam"ma\, n.; pl. {Mamm[ae]}. [L. mamma breast.] (Anat.)
   A glandular organ for secreting milk, characteristic of all
   mammals, but usually rudimentary in the male; a mammary
   gland; a breast; under; bag.

Source : WordNet®

mamma
     n 1: informal terms for a mother [syn: {ma}, {mama}, {mom}, {momma},
           {mommy}, {mammy}, {mum}, {mummy}, {mater}]
     2: milk-secreting organ of female mammals [syn: {mammary gland}]
     [also: {mammae} (pl)]