The Collaborative International Dictionary of English v.0.48:

Squash \Squash\, n.
   1. Something soft and easily crushed; especially, an unripe
      pod of pease.
      [1913 Webster]

            Not yet old enough for a man, nor young enough for a
            boy; as a squash is before 't is a peascod. --Shak.
      [1913 Webster]

   2. Hence, something unripe or soft; -- used in contempt.
      "This squash, this gentleman." --Shak.
      [1913 Webster]

   3. A sudden fall of a heavy, soft body; also, a shock of soft
      bodies. --Arbuthnot.
      [1913 Webster]

            My fall was stopped by a terrible squash. --Swift.
      [1913 Webster]

   4. A game much like rackets, played in a walled court with
      soft rubber balls and bats like tennis rackets; -- called
      also squash rackets.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Squash \Squash\ (skw[o^]sh), n. [Cf. Musquash.] (Zool.)
   An American animal allied to the weasel. [Obs.] --Goldsmith.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Squash \Squash\, n. [Massachusetts Indian asq, pl. asquash, raw,
   green, immature, applied to fruit and vegetables which were
   used when green, or without cooking; askutasquash vine
   apple.] (Bot.)
   A plant and its fruit of the genus Cucurbita, or gourd
   kind.
   [1913 Webster]

   Note: The species are much confused. The long-neck squash is
         called Cucurbita verrucosa, the Barbary or China
         squash, Cucurbita moschata, and the great winter
         squash, Cucurbita maxima, but the distinctions are
         not clear.
         [1913 Webster]

   Squash beetle (Zool.), a small American beetle (Diabrotica
      vittata, syn. Galeruca vittata) which is often abundant
      and very injurious to the leaves of squash, cucumber, etc.
      It is striped with yellow and black. The name is applied
      also to other allied species.

   Squash bug (Zool.), a large black American hemipterous
      insect (Coreus tristis syn. Anasa tristis) injurious
      to squash vines.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Squash \Squash\, v. t. [imp. & p. p. Squashed (skw[o^]sht); p.
   pr. & vb. n. Squashing.] [OE. squachen, OF. escachier,
   esquachier, to squash, to crush, F. ['e]cacher, perhaps from
   (assumed) LL. excoacticare, fr. L. ex + coactare to
   constrain, from cogere, coactum, to compel. Cf. Cogent,
   Squat, v. i.]
   To beat or press into pulp or a flat mass; to crush.
   [1913 Webster]

WordNet (r) 3.0 (2006):

squash
    n 1: any of numerous annual trailing plants of the genus
         Cucurbita grown for their fleshy edible fruits [syn:
         squash, squash vine]
    2: edible fruit of a squash plant; eaten as a vegetable
    3: a game played in an enclosed court by two or four players who
       strike the ball with long-handled rackets [syn: squash,
       squash racquets, squash rackets]
    v 1: to compress with violence, out of natural shape or
         condition; "crush an aluminum can"; "squeeze a lemon" [syn:
         squash, crush, squelch, mash, squeeze]

Moby Thesaurus II by Grady Ward, 1.0:

260 Moby Thesaurus words for "squash":
   abrade, annihilate, answer, answer conclusively, argue down,
   asphyxiate, assibilate, assibilation, atomize, bear, beat,
   black out, bottle up, bray, break into pieces, break to pieces,
   break up, brecciate, bruise, butter, buzz, cataplasm, censor, chew,
   choke, choke off, clamp down on, clay, comminute, confound,
   confute, contradict, contriturate, controvert, cork, cork up,
   crack down on, cram, crash, crowd, crumb, crumble, crunch, crush,
   cushion, cut to pieces, damp down, defeat, demolish, dental pulp,
   deny, diffuse, disintegrate, dismiss, disperse, dispose of,
   disrupt, drove, drown, dumbfound, ease, effervesce, effervescence,
   effervescing, extinguish, finish, fission, fizz, fizzle, fizzling,
   floor, flour, fluff, fragment, frication, frictional rustling, gag,
   gentle, grain, granulate, granulize, grate, grind, grind to powder,
   gumbo, hiss, hissing, hold down, horde, hugger-mugger, hush,
   hush up, hush-hush, hushing, jam, jump on, keep down, keep under,
   kill, knead, laxate, levigate, limber, limber up, lisp, loosen,
   macerate, make mincemeat of, mash, massage, masticate, mellow,
   milden, mill, mince, mire, mollify, muck, mud, muffle, multitude,
   mush, muzzle, nonplus, ooze, overthrow, overturn, overwhelm,
   paper pulp, parry, paste, pestle, pith, plaster, plump, porridge,
   poultice, pound, pour water on, powder, press, pudding, pulp,
   pulp lead, pulpify, pulpwood, pulverize, push, put down, put out,
   put to silence, quash, quell, quench, quiet, quieten, rag pulp,
   rebut, reduce to powder, reduce to silence, refute, relax, repress,
   rhonchus, sauce, scatter, scrunch, settle, shake up, shard,
   shatter, shiver, shred, shush, shushing, shut down on, shut up,
   sibilance, sibilate, sibilation, siffle, sigmatism, silence, siss,
   sissing, sit down on, sit on, sizz, sizzle, sizzling, slime, slip,
   slob, slop, slosh, sludge, slush, smash, smash all opposition,
   smash up, smother, sneeze, sneezing, sniff, sniffle, snore, snort,
   snuff, snuff out, snuffle, soft-pedal, soften, soften up, spit,
   splinter, splutter, sponge, sputter, squab, squeeze, squelch,
   squish, stamp out, stanch, sternutation, stertor, stifle, still,
   strangle, strike dumb, stultify, subdue, subvert, suffocate,
   sulfate pulp, sulfite pulp, supple, suppress, swill, swish,
   tenderize, throng, throttle, tone down, trample out,
   trample underfoot, triturate, tune down, undermine, upset, wheeze,
   whish, whistle, whistling, white lead, white noise, whiz, whoosh,
   wood pulp, zip