Source : Webster's Revised Unabridged Dictionary (1913)

Clash \Clash\, v. i. [imp. & p. p. {Clashed}; p. pr. & vb. n.
   {Clashing}.] [Of imitative origin; cf. G. klatschen, Prov. G.
   kleschen, D. kletsen, Dan. klaske, E. clack.]
   1. To make a noise by striking against something; to dash
      noisily together.

   2. To meet in opposition; to act in a contrary direction; to
      come onto collision; to interfere.

            However some of his interests might clash with those
            of the chief adjacent colony.         --Palfrey.

Clash \Clash\, v. t.
   To strike noisily against or together.

Clash \Clash\ n.
   1. A loud noise resulting from collision; a noisy collision
      of bodies; a collision.

            The roll of cannon and clash of arms. --Tennyson.

   2. Opposition; contradiction; as between differing or
      contending interests, views, purposes, etc.

            Clashes between popes and kings.      --Denham.

Source : WordNet®

clash
     n 1: a loud resonant repeating noise; "he could hear the clang of
          distant bells" [syn: {clang}, {clangor}, {clangour}, {clangoring},
           {clank}, {crash}]
     2: a state of conflict between persons [syn: {friction}]
     3: a state of conflict between colors; "her dress was a
        disturbing clash of colors"
     4: a minor short-term fight [syn: {brush}, {encounter}, {skirmish}]
     v 1: crash together with violent impact; "The cars collided";
          "Two meteors clashed" [syn: {collide}]
     2: be incompatible; be or come into conflict; "These colors
        clash" [syn: {jar}, {collide}]
     3: disagree violently; "We clashed over the new farm policies"