Source : Webster's Revised Unabridged Dictionary (1913)

Introvert \In`tro*vert"\, v. t. [imp. & p. p. {Introverted}; p.
   pr. & vb. n. {Introverting}.] [Pref. intro- + L. vertere,
   versum, to turn.]
   1. To turn or bend inward. ``Introverted toes.'' --Cowper.

   2. To look within; to introspect. --Lew Wallace.

Source : WordNet®

introvert
     n : (psychology) a person who tends to shrink from social
         contacts and to become preoccupied with their own
         thoughts [ant: {extrovert}]
     v 1: fold inwards; "some organs can invaginate" [syn: {invaginate}]
     2: turn inside; "He introverted his feelings"