Source : Webster's Revised Unabridged Dictionary (1913)

Adventurer \Ad*ven"tur*er\, n. [Cf. F. aventurier.]
   1. One who adventures; as, the merchant adventurers; one who
      seeks his fortune in new and hazardous or perilous
      enterprises.

   2. A social pretender on the lookout for advancement.

Source : WordNet®

adventurer
     n 1: a person who enjoys taking risks [syn: {venturer}]
     2: someone who travels into little known regions (especially
        for some scientific purpose) [syn: {explorer}]