afoul

American  

[uh-faul] / əˈfaʊl /

adverb

1. in a state of collision or entanglement.

   a ship with its shrouds afoul.

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idioms

1. run / come / fall afoul of,

   1. to become entangled with.

      The boat ran afoul of the seaweed.

   2. to come into conflict with.

      The business had fallen afoul of the new government regulations.

afoul British  

/ əˈfaʊl /

adverb

1. (usually foll by of) in or into a state of difficulty, confusion, or conflict (with)

2. (often foll by of) in or into an entanglement or collision (with) (often in the phrase run afoul of )

   a yacht with its sails afoul

   the boat ran afoul of a steamer

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Etymology

Origin of afoul

An Americanism dating back to 1800–10; a- ¹ + foul

Explanation

If something goes afoul, it goes badly wrong. When a prank falls afoul of the law, it crosses the line from just a joke to something much more serious. Use the adjective afoul to describe things that conflict or clash. If a politician goes afoul of the rules about using taxpayer money for person items, she's bound to pay for it in votes. Likewise, a party guest might accidentally go afoul of the etiquette about how much candy to grab from a fallen piñata. The original nineteenth century meaning of afoul was nautical, describing tangled ropes or lines on a ship.

Example Sentences

See Examples For:

afoul

Warren also said that Bilt’s practice of immediately debiting rent payments may have run afoul of the 2009 Credit Card Accountability Responsibility and Disclosure Act’s disclosure requirements for credit cards.

From Salon ● Sep. 1, 2026

“Running afoul of tax laws can be a costly financial mistake,” Balcom said.

From MarketWatch ● Aug. 8, 2026

“There’s absolutely nothing in here that runs afoul of any of the Supreme Court’s opinions on the subject.”

From Los Angeles Times ● Aug. 7, 2026

That arrangement ran afoul of the NFL’s governance rules—and the league had been pressuring Jody Allen to follow through with a sale.

From The Wall Street Journal ● Jul. 12, 2026

It seems the boy is always running afoul of a pack of shamblers in the midst of his Missouri adventures, and the boy’s derring-do reminds me of my own exploits.

From "Dread Nation" by Justina Ireland