Word Study
tummy
OXFORD DICTIONARY
tummy, n. (pl. -ies) colloq. the stomach.
Idiom
tummy-button the navel.
Etymology
childish pronunc. of STOMACH
THESAURUS
tummy
abdomen, abomasum, bay window, beerbelly, belly, breadbasket, craw, crop, diaphragm, embonpoint, first stomach, gizzard, gullet, gut, honeycomb stomach, kishkes, manyplies, maw, midriff, omasum, paunch, pot, potbelly, potgut, psalterium, pusgut, rennet bag, reticulum, rumen, second stomach, spare tire, stomach, swagbelly, third stomach, tum-tum, underbelly, venter, ventripotenceFor further exploring for "tummy" in Webster Dictionary Online