The Collaborative International Dictionary of English v.0.48:

Spit \Spit\, v. t. [imp. & p. p. Spit (Spat, archaic); p.
   pr. & vb. n. Spitting.] [AS. spittan; akin to G.
   sp["u]tzen, Dan. spytte, Sw. spotta,Icel. sp?ta, and prob. E.
   spew. The past tense spat is due to AS. sp?tte, from sp?tan
   to spit. Cf. Spat, n., Spew, Spawl, Spot, n.]
   1. To eject from the mouth; to throw out, as saliva or other
      matter, from the mouth. "Thus spit I out my venom."
      --Chaucer.
      [1913 Webster]

   2. To eject; to throw out; to belch.
      [1913 Webster]

   Note: Spitted was sometimes used as the preterit and the past
         participle. "He . . . shall be mocked, and spitefully
         entreated, and spitted on." --Luke xviii. 32.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spat \Spat\,
   imp. of Spit. [Obs. or R.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spat \Spat\, n. [From the root of spit; hence, literally, that
   which is ejected.]
   A young oyster or other bivalve mollusk, both before and
   after it first becomes adherent, or such young, collectively.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spat \Spat\, v. i. & t.
   To emit spawn; to emit, as spawn.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spat \Spat\, n. [Cf. Pat.]
   1. A light blow with something flat. [U.S. & Prov. Eng.]
      [1913 Webster]

   2. Hence, a petty combat, esp. a verbal one; a little
      quarrel, dispute, or dissension. [U. S.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spat \Spat\, v. i.
   To dispute. [R.] --Smart.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spat \Spat\, v. t. [imp. & p. p. Spatted; p. pr. & vb. n.
   Spatting.]
   To slap, as with the open hand; to clap together; as the
   hands. [Local, U.S.]
   [1913 Webster]

         Little Isabel leaped up and down, spatting her hands.
                                                  --Judd.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spat \Spat\, n. [Short for Spatterdash.]
   1. A legging; a gaiter. [Scot. & Dial. Eng.]
      [Webster 1913 Suppl.]

   2. A kind of short cloth or leather gaiter worn over the
      upper part of the shoe and fastened beneath the instep; --
      chiefly in pl.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

spat
    n 1: a quarrel about petty points [syn: bicker, bickering,
         spat, tiff, squabble, pettifoggery, fuss]
    2: a cloth covering (a legging) that covers the instep and
       ankles [syn: spat, gaiter]
    3: a young oyster or other bivalve
    v 1: come down like raindrops; "Bullets were spatting down on
         us"
    2: become permanently attached; "mollusks or oysters spat"
    3: strike with a sound like that of falling rain; "Bullets were
       spatting the leaves"
    4: clap one's hands or shout after performances to indicate
       approval [syn: applaud, clap, spat, acclaim] [ant:
       boo, hiss]
    5: engage in a brief and petty quarrel
    6: spawn; "oysters spat"
    7: clap one's hands together; "The children were clapping to the
       music" [syn: clap, spat]