A legionnaire is literally a "chosen man" — from Latin legere (to choose), the same root that gives us election, lecture, legend, and even the verb to read.
A member of a legion, especially the French Foreign Legion or the ancient Roman legions; also, a member of the American Legion or similar veterans' organization.
From French légionnaire, from Latin legiōnārius (of or belonging to a legion), from legiō (legion, a body of soldiers), from legere (to choose, to gather, to read), from PIE *leǵ- (to collect, to gather). Key roots: *leǵ- (Proto-Indo-European: "to collect, to gather, to choose").
The root behind legionnaire — Latin legere (to choose, to gather) — also gives us lecture (a reading), legend (things to be read), legal (chosen rules), elegant (chosen with care), elect (chosen out), college (chosen together), and even lesson (a reading). Roman legionaries were originally "chosen men" — citizens selected for military service, not volunteers or mercenaries. The French Foreign Legion, founded in 1831, deliberately invokes