To make filthy; to defile; to daub; to dirty; to soil; as,
to foul the face or hands with mire.

To incrust (the bore of a gun) with burnt powder in the
process of firing.

Loathsome; disgusting; as, a foul disease.

Having freedom of motion interfered with by collision or
entanglement; entangled; – opposed to clear; as, a rope or cable may
get foul while paying it out.

Not favorable; unpropitious; not fair or advantageous;
as, a foul wind; a foul road; cloudy or rainy; stormy; not fair; –
said of the weather, sky, etc.

Hateful; detestable; shameful; odious; wretched.

Covered with, or containing, extraneous matter which is
injurious, noxious, offensive, or obstructive; filthy; dirty; not
clean; polluted; nasty; defiled; as, a foul cloth; foul hands; a foul
chimney; foul air; a ship’s bottom is foul when overgrown with
barnacles; a gun becomes foul from repeated firing; a well is foul with
polluted water.

A bird.

Scurrilous; obscene or profane; abusive; as, foul words;
foul language.

Not conformed to the established rules and customs of a
game, conflict, test, etc.; unfair; dishonest; dishonorable; cheating;
as, foul play.