Meaning

noun an act that violates the rules of a sport

verb hit a foul ball

verb make impure

originInherited from Middle English ffoul, foul, foull, fowel, fowle, fuyle, voul, vul, from Old English fūl (“foul, dirty, unclean, impure, vile, corrupt, rotten, stinking, guilty”), from Proto-West Germanic *fūl, from Proto-Germanic *fūlaz (“foul, rotten”), from Proto-Indo-European *puH- (“foul, rotten”). Cognates Cognate with Central Franconian fuul (“putrid, rotten; lazy, workshy”), Cimbrian baul,…

Etymology from Wiktionary, CC BY-SA 3.0