The Collaborative International Dictionary of English v.0.48:

Chevalier \Che`va*lier"\, n. [F., fr. LL. caballarius. See
   Cavaller.]
   1. A horseman; a knight; a gallant young man. "Mount,
      chevaliers; to arms." --Shak.
      [1913 Webster]

   2. A member of certain orders of knighthood.
      [1913 Webster]

   Chevalier d'industrie[F.], one who lives by persevering
      fraud; a pickpocket; a sharper.

   The Chevalier St. George (Eng. Hist.), James Francis Edward
      Stuart (son of James II.), called "The Pretender."

   The Young Chevalier, Charles Edward Stuart, son of the
      Chevalier St. George.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Chevalier
    n 1: French actor and cabaret singer (1888-1972) [syn:
         Chevalier, Maurice Chevalier]
    2: a gallant or courtly gentleman [syn: cavalier, chevalier]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "chevalier":
   Bayard, Don Quixote, Gawain, Lancelot, Ritter, Sidney, Sir Galahad,
   bachelor, banneret, baronet, broncobuster, buckaroo, caballero,
   cavalier, cavalryman, circus rider, companion, cowboy, cowgirl,
   cowpuncher, equestrian, equestrienne, gallant, gaucho,
   horse soldier, horseback rider, horsebacker, horseman, horsewoman,
   jockey, knight, knight bachelor, knight banneret, knight baronet,
   knight-errant, mounted policeman, postboy, postilion, puncher,
   rider, roughrider, steeplechaser, trick rider, vaquero