Source : Webster's Revised Unabridged Dictionary (1913)

Teat \Teat\, n. [OE. tete, titte, AS. tit, titt; akin to LG. &
   OD. titte, D. tet, G. zitze: cf. F. tette, probably of
   Teutonic origin.]
   1. The protuberance through which milk is drawn from the
      udder or breast of a mammal; a nipple; a pap; a mammilla;
      a dug; a tit.

   2. (Mach.) A small protuberance or nozzle resembling the teat
      of an animal.

Source : WordNet®

teat
     n : the small projection of a mammary gland [syn: {nipple}, {mammilla},
          {mamilla}, {pap}, {tit}]