foul

adjective

• 1offensive to the senses, especially through having a disgusting smell or taste or being dirty:a foul odour his foul breath
• informal very disagreeable or unpleasant:the news had put Michelle in a foul mood

• 2wicked or immoral:murder most foul
• (of language) obscene: foul oaths foul language
• done contrary to the rules of a sport:a foul tackle

• 3containing or full of noxious matter; polluted:foul, swampy water
• (foul with) clogged or choked with:the land was foul with weeds
• Nautical (of a rope or anchor) entangled.
• (of a ship’s bottom) overgrown with weed, barnacles, or similar matter.

• 4(of the weather) wet and stormy: he walked in fair and foul weather the weather turned foul
• Sailing (of wind or tide) opposed to one’s desired course: it sometimes becomes advantageous to anchor during the periods of foul tide

noun

• (in sport) an unfair or invalid stroke or piece of play, especially one involving interference with an opponent: the midfielder was booked for a foul on Ford
• a collision or entanglement in riding, rowing, or running.

adverb

• contrary to the rules; unfairly.

verb

• 1make foul or dirty; pollute:factories which fouled the atmosphere
• (of an animal) make (something) dirty with excrement:make sure that your pet never fouls paths
• (foul oneself) (of a person) defecate involuntarily.

• 2(in sport) commit a foul against (an opponent): United claim their keeper was fouled

• 3(of a ship) collide with or interfere with the passage of (another): the ships became overcrowded and fouled each other
• cause (a cable, anchor, or other object) to become entangled or jammed:watch out for driftwood which might foul up the engine