pellet n.

mid-14c., "downy plumage;" late 15c, "fine, soft hair," from Anglo-French pyle or Middle Dutch pijl, both from Latin pilus "a hair" (source of Italian pelo, Old French pel), a word of uncertain origin. Phonological evidence rules out transmission of the English word via Old French cognate peil, poil. Meaning "soft, raised surface of a regular and closely set kind upon cloth" is from 1560s.

"to strike repeatedly" (with something), c. 1500, a word of unknown origin; according to one old theory it is perhaps from early 13c. pelten "to strike," a variant of pilten "to thrust, strike," from an unrecorded Old English *pyltan, from Medieval Latin *pultiare, from Latin pultare "to beat, knock, strike," or [Watkins] pellere "to push, drive, strike" (from PIE root *pel- (5) "to thrust, strike, drive"). OED doubts this. Or it might be from Old French peloter "to strike with a ball," from pelote "ball" (see pellet (n.)) [Klein].

From 1680s as "to go on throwing (missiles) with intent to strike." The meaning "proceed rapidly and without intermission" (1831) is from the notion of beating the ground with rapid steps. Related: Pelted; pelting.

1630s, "a small body of soldiers acting together but separate from the main body of troops," from French peloton "platoon, group of people," literally "little ball" (15c.), hence, "agglomeration," diminutive of Old French pelote "ball" (see pellet). Football sense of "group of players trained to act as a unit on the field" is by 1941.