mid-14c., pelot, "any little ball," as of a medicine or food, but especially a little metallic ball used as a missile, from Old French pelote "small ball" (11c.) and directly from Medieval Latin pelotis, from Vulgar Latin *pilotta, diminutive of Latin pila "ball, playing ball, the game of ball," perhaps originally "ball of hair," from pilus "hair" (see pile (n.3)).