Source : Webster's Revised Unabridged Dictionary (1913)

Titty \Tit"ty\, n.
   A little teat; a nipple. [Familiar]

Source : WordNet®

titty
     n : either of two soft fleshy milk-secreting glandular organs on
         the chest of a woman [syn: {breast}, {bosom}, {knocker},
         {boob}, {tit}]