The Collaborative International Dictionary of English v.0.48:

Vomit \Vom"it\, n. [L. vomitus, from vomere, vomitum, to vomit;
   akin to Gr. ?, Skr. vam, Lith. vemiti. Cf. Emetic,
   Vomito.]
   [1913 Webster]
   1. Matter that is vomited; esp., matter ejected from the
      stomach through the mouth.
      [1913 Webster]

            Like vomit from his yawning entrails poured.
                                                  --Sandys.
      [1913 Webster]

   2. (Med.) That which excites vomiting; an emetic.
      [1913 Webster]

            He gives your Hollander a vomit.      --Shak.
      [1913 Webster]

   Black vomit. (Med.) See in the Vocabulary.

   Vomit nut, nux vomica.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vomit \Vom"it\, v. i. [imp. & p. p. Vomited; p. pr. & vb. n.
   Vomiting.] [Cf. L. vomere, vomitum, and v. freq. vomitare.
   See Vomit, n.]
   To eject the contents of the stomach by the mouth; to puke;
   to spew.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vomit \Vom"it\, v. t.
   1. To throw up; to eject from the stomach through the mouth;
      to disgorge; to puke; to spew out; -- often followed by up
      or out.
      [1913 Webster]

            The fish . . . vomited out Jonah upon the dry land.
                                                  --Jonah ii.
                                                  10.
      [1913 Webster]

   2. Hence, to eject from any hollow place; to belch forth; to
      emit; to throw forth; as, volcanoes vomit flame, stones,
      etc.
      [1913 Webster]

            Like the sons of Vulcan, vomit smoke. --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

vomit
    n 1: the matter ejected in vomiting [syn: vomit, vomitus,
         puke, barf]
    2: a medicine that induces nausea and vomiting [syn: emetic,
       vomit, vomitive, nauseant]
    3: the reflex act of ejecting the contents of the stomach
       through the mouth [syn: vomit, vomiting, emesis,
       regurgitation, disgorgement, puking]
    v 1: eject the contents of the stomach through the mouth; "After
         drinking too much, the students vomited"; "He purged
         continuously"; "The patient regurgitated the food we gave
         him last night" [syn: vomit, vomit up, purge, cast,
         sick, cat, be sick, disgorge, regorge, retch,
         puke, barf, spew, spue, chuck, upchuck, honk,
         regurgitate, throw up] [ant: keep down]

Moby Thesaurus II by Grady Ward, 1.0:

85 Moby Thesaurus words for "vomit":
   barf, be nauseated, be seasick, be sick, belch, blow open,
   blow out, break out, bring up, burst forth, burst out, cascade,
   cast, cat, choke on, chuck up, discharge, disgorge, disgorgement,
   drain, drain out, egest, egesta, egestion, eject, emetic, empty,
   eruct, erupt, exhaust, expel, feed the fish, feel disgust,
   find vent, flow, flow out, gag, gagging, gush, gush out, heave,
   heave the gorge, heaves, heaving, hurl forth, jet, keck, nausea,
   nauseant, outflow, outpour, play, pour, pour out, puke,
   regurgitate, regurgitation, reject, retch, run out, shoot, sick up,
   sicken at, sluice out, spew, spew out, spit, spout, spout out,
   spray, spritz, spurt, spurtle, spy, squirt, surge, throw up,
   upchuck, vomit forth, vomit out, vomiting, vomition, vomitive,
   well, well out