afoul

American  

[uh-foul] / 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

Bloomberg even called on the city’s Campaign Finance Board to investigate whether their anti-stadium ad spending was running afoul of election laws, though nothing ever came of it.

From The Wall Street Journal • May 15, 2026

Phelan, a former businessman with close ties to Trump who helped fundraising efforts for his presidential campaigns, ran afoul of both the president and Hegseth during his tenure, according to CNN.

From Salon • May 1, 2026

He ran afoul of some in the orchestra and of its imperious head, Ernest Fleischmann.

From Los Angeles Times • Apr. 24, 2026

They would be running afoul of sanctions if they transact with Iran.

From Barron's • Apr. 22, 2026

In Philadelphia, she heard stories about three different runaways who had run afoul of the law, for these stories were being told everywhere —North and South.

From "Harriet Tubman: Conductor on the Underground Railroad" by Ann Petry