Source : Webster's Revised Unabridged Dictionary (1913)

Squash \Squash\, v. t. [imp. & p. p. {Squashed}; p. pr. & vb. n.
   {Squashing}.] [OE. squashen, 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.

Source : WordNet®

squashed
     adj : that has been violently compressed; "the squashed looking
           nakedness of the fledgling birds"