1649, "small number of military men detailed for some purpose," from Fr. esquade, from M.Fr. escadre, from Sp. escuadra or It. squadra "battalion," lit. "square," from V.L. *exquadra (see square). Until the introduction of automatic weapons, infantry troops tended to fight
in a square formation to repel cavalry or superior forces. Sports sense is recorded from 1902.