Source : Webster's Revised Unabridged Dictionary (1913)

Treble \Tre"ble\, v. t. [imp. & p. p. {Trebled}; p. pr. & vb. n.
   {Trebling}.]
   1. To make thrice as much; to make threefold. ``Love trebled
      life.'' --Tennyson.

   2. To utter in a treble key; to whine. [Obs.]

            He outrageously (When I accused him) trebled his
            reply.                                --Chapman.