Source : Webster's Revised Unabridged Dictionary (1913)

Breast \Breast\ (br[e^]st), n. [OE. brest, breost, As.
   bre['o]st; akin to Icel. brj[=o]st, Sw. br["o]st, Dan. bryst,
   Goth. brusts, OS. briost, D. borst, G. brust.]
   1. The fore part of the body, between the neck and the belly;
      the chest; as, the breast of a man or of a horse.

   2. Either one of the protuberant glands, situated on the
      front of the chest or thorax in the female of man and of
      some other mammalia, in which milk is secreted for the
      nourishment of the young; a mamma; a teat.

            My brother, that sucked the breasts of my mother.
                                                  --Cant. viii.
                                                  1.

   3. Anything resembling the human breast, or bosom; the front
      or forward part of anything; as, a chimney breast; a plow
      breast; the breast of a hill.

            Mountains on whose barren breast The laboring clouds
            do often rest.                        --Milton.

   4. (Mining)
      (a) The face of a coal working.
      (b) The front of a furnace.

   5. The seat of consciousness; the repository of thought and
      self-consciousness, or of secrets; the seat of the
      affections and passions; the heart.

            He has a loyal breast.                --Shak.

   6. The power of singing; a musical voice; -- so called,
      probably, from the connection of the voice with the lungs,
      which lie within the breast. [Obs.]

            By my troth, the fool has an excellent breast.
                                                  --Shak.

   {Breast drill}, a portable drilling machine, provided with a
      breastplate, for forcing the drill against the work.

   {Breast pang}. See {Angina pectoris}, under {Angina}.

   {To make a clean breast}, to disclose the secrets which weigh
      upon one; to make full confession.

Breast \Breast\, v. t. [imp. & p. p.{Breasted}; p. pr. & vb. n.
   {Breasting}.]
   To meet, with the breast; to struggle with or oppose
   manfully; as, to breast the storm or waves.

Brest \Brest\, Breast \Breast\, n. (Arch.)
   A torus. [Obs.]

Source : WordNet®

breast
     n 1: the front part of the trunk from the neck to the abdomen;
          "he beat his breast in anger"
     2: either of two soft fleshy milk-secreting glandular organs on
        the chest of a woman [syn: {bosom}, {knocker}, {boob}, {tit},
         {titty}]
     3: meat carved from the breast of a fowl [syn: {white meat}]

breast
     v 1: meet at breast level; "The runner breasted the tape"
     2: reach the summit; "They breasted the mountain"
     3: confront bodily; "breast the storm" [syn: {front}]