Word Origin & History
1591, from M.Fr. esprit "spirit, mind," from O.Fr. espirit, from L. spiritus "spirit." Esprit de corps first recorded 1780. Fr. also has the excellent phrase esprit de l'escalier, lit. "spirit of the staircase," defined in OED as, "a retort or remark that occurs to a person after the opportunity to make
it has passed."