Source : Webster's Revised Unabridged Dictionary (1913)

Soliloquize \So*lil"o*quize\, v. i. [imp. & p. p.
   {Soliloquized}; p. pr. & vb. n. {Soliloquizing}.]
   To utter a soliloquy; to talk to one's self.

Source : WordNet®

soliloquize
     v : talk to oneself [syn: {monologuize}, {monologuise}, {soliloquise}]