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

See Examples For:

afoul

If the founder sets up an additional trust jointly for John and Jane, and another for John and Joan and another for Jane and Joan, that could run afoul of the forthcoming rules.

From The Wall Street Journal ● Jun. 29, 2026

Ahead of the game, the FAA warned drone operators that they could get their drone seized, face federal criminal charges and fines of up to $100,000 if they run afoul of these restrictions.

From Los Angeles Times ● Jun. 14, 2026

But Rossetti’s comments ran afoul of his boss, the Catholic archbishop of Washington, D.C., who announced Wednesday he had “removed” Rossetti from his position as an exorcist.

From Slate ● Jun. 8, 2026

While both these approaches would almost certainly run afoul of labor laws, the new tax law has introduced a temptation that simply wasn’t there before.

From MarketWatch ● Jun. 4, 2026

He gestured toward the man who had ran afoul of Falconer, and who had stood up for me before the other players.

From "The Shakespeare Stealer" by Gary L. Blackwood