Source : Webster's Revised Unabridged Dictionary (1913)

Pantaloon \Pan`ta*loon"\, n. [F. pantalon, fr. It. pantalone, a
   masked character in the Italian comedy, who wore breeches and
   stockings that were all of one piece, from Pantaleone, the
   patron saint of Venice, which, as a baptismal name, is very
   frequent among the Venetians, and is applied to them by the
   other Italians as a nickname, fr. Gr. ?, lit., all lion, a
   Greek personal name.]
   1. A ridiculous character, or an old dotard, in the Italian
      comedy; also, a buffoon in pantomimes. --Addison.

            The sixth age shifts Into the lean and slippered
            pantaloon.                            --Shak.

   2. pl. A bifurcated garment for a man, covering the body from
      the waist downwards, and consisting of breeches and
      stockings in one.

   3. pl. In recent times, same as {Trousers}.

Source : WordNet®

Pantaloon
     n 1: a buffoon in modern pantomimes; the butt of jokes
     2: a character in the commedia dell'arte; portrayed as a
        foolish old man
     3: trousers worn in former times