Source : Webster's Revised Unabridged Dictionary (1913)

Gendarme \Gen`darme"\, n.; pl. {Gendarmes}, or {Gens d'armes}.
   [F.]
   1. (Mil.) One of a body of heavy cavalry. [Obs.] [France]

   2. An armed policeman in France. --Thackeray.

Source : WordNet®

gendarme
     n : a French policeman