13th cent. Old Spanish pellota. Borrowed from either Old French pelote or Old Occitan pelota 'id.' It replaced the native Old Spanish pella (pellota also existed, though rarely used). From Vulgar Latin *pilotta "little ball," a diminutive of Latin pila "ball."
Of unknown origin.
Catalan pila, French pile, Italian pila
Latin pilus "hair," compilare "to steal"