"French military police," 1796, from French (they were first organized in France 1790); earlier "mounted trooper" (1540s), from French contraction (14c.) of gens d'armes "men at arms." Gens is plural of gent "nation, people," from Latin gentem (nominative gens) "race, nation, people" (from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups). For armes see arm (n.2). Related: Gendarmerie, gendarmery. French also had gens de (la) robe "lawyers," which was sometimes borrowed in English.