means A person used by others to serve their own ends, with little power or choice of their own; also the lowest-ranked chess piece, or to leave an item as security for a loan.

from From Old French 'paon' or 'peon,' meaning a foot soldier, which traces back to Latin 'pedo, pedonem' — 'one who goes on foot' (from 'pes, pedis,' foot, the same root behind 'pedal' and 'pedestrian'). The expendable infantryman became the expendable chess piece, and from there the figure of speech for anyone moved about by someone more powerful. The unrelated 'pawn' meaning a pledge or loan comes through a separate French word 'pan,' a pledge or surety.