foul
Meaning
offensive or disgusting because of decay or dirt
(in sports) breaking the rules; unfair
make foul or dirty; pollute
(in sports) commit a foul against (an opponent)
(in sports) an unfair or invalid act against an opponent
Usage
the water in the harbor was foul with oil and garbage.
the player was sent off for a serious foul.
factories foul the air with smoke and chemical fumes.
Etymology
the word "foul" originates from the old english "fūl," meaning offensive, dirty, or rotten. this old english term is cognate with old norse "fúll" and old high german "fūl," all sharing the same core sense of putridity. these germanic forms descend from the proto-germanic "fūlaz," which in turn is derived from the proto-indo-european root "pu-," meaning to rot or decay, a root also connected to pus and putrid. the semantic journey from literal physical decay to metaphorical senses of moral offensiveness and rule-breaking in sports illustrates a classic pattern of meaning extension from the concrete to the abstract.
Analysis
the word is a simplex form derived from a single old english root.