grossly offensive to the senses; disgustingly loathsome; noisome

a foul smell.

containing or characterized by offensive or noisome matter

foul air; foul stagnant water.

filthy or dirty, as places, receptacles, clothes, etc.

muddy, as a road.

clogged or obstructed with foreign matter

a foul gas jet.

unfavorable or stormy

foul weather.

contrary, violent, or unfavorable, as the wind.

grossly offensive in a moral sense.

abominable, wicked, or vile, as deeds, crime, slander, etc.

scurrilous, profane, or obscene; offensive

foul language.

contrary to the rules or established usages, as of a sport or game; unfair

a foul blow.

Baseball . pertaining to a foul ball or a foul line.

limited in freedom of movement by obstruction, entanglement, etc.

a foul anchor.

abounding in errors or in marks of correction, as a printer's proof, manuscript, or the like.

Nautical .

(of the underwater portion of a hull) encrusted and impeded with barnacles, seaweed, etc.

(of a mooring place) involving inconveniences and dangers, as of colliding with vessels or other objects when swinging with the tide.

(of the bottom of a body of water) affording a poor hold for an anchor ( opposed to clean ).

North England and Scot. . not fair; ugly or unattractive.

Obsolete . disfigured.

in a foul manner; vilely; unfairly.

Baseball . into foul territory; so as to be foul

It looked like a homer when he hit it, but it went foul.

something that is foul.

a collision or entanglement

a foul between two racing sculls.

a violation of the rules of a sport or game

The referee called it a foul.

Baseball . foul ball.

to make foul; defile; soil.

to clog or obstruct, as a chimney or the bore of a gun.

to collide with.

to cause to become entangled or caught, as a rope.

to defile; dishonor; disgrace

His reputation had been fouled by unfounded accusations.

Nautical . (of barnacles, seaweed, etc.) to cling to (a hull) so as to encumber.

Baseball . to hit (a pitched ball) foul (often fol. by off or away )

He fouled off two curves before being struck out on a fastball.

to become foul.

Nautical . to come into collision, as two boats.

to become entangled or clogged

The rope fouled.

Sports . to make a foul play; give a foul blow.

Baseball . to hit a foul ball. ?

foul out,

Baseball . to be put out by hitting a foul ball caught on the fly by a player on the opposing team.

Basketball . to be expelled from a game for having committed more fouls than is allowed.

foul up, Informal . to cause confusion or disorder; bungle; spoil. ?

fall foul or afoul of

to collide with, as ships.

to come into conflict with; quarrel.

to make an attack; assault.

foul one's nest. to dishonor one's own home, family

or the like.

run foul or afoul of

to come into collision or controversy with

to run foul of the press.