elan (n.)

"vivacity," 1877, from French élan (16c.), "spring, bound, impetus," noun derived from élancer "to shoot, incite" (trans.); "rush forward, dart" (intrans.), from Old French elancer, from e- "out" (see ex-) + lancer "to throw," originally "to throw a lance," from Late Latin lanceare, from Latin lancea (see lance (n.)).