The Collaborative International Dictionary of English v.0.48:

extrovert \extrovert\ n. (Psychol.)
   A person who is extroverted; a person who is marked by an
   interest in others or concerned primarily with external
   reality. Contrasted with introvert.
   [WordNet 1.5 +PJC] extroverted

WordNet (r) 3.0 (2006):

extrovert
    adj 1: being concerned with the social and physical environment
           [syn: extrovert, extravert, extroverted,
           extraverted, extrovertive, extravertive]
    n 1: (psychology) a person concerned more with practical
         realities than with inner thoughts and feelings [syn:
         extrovert, extravert] [ant: introvert]