run afoul of

Idioms

Also, run foul of. Come into conflict with, as in If you keep parking illegally you'll run afoul of the police. This expression originated in the late 1600s, when it was applied to a vessel colliding or becoming entangled with another vessel, but at the same time it was transferred to non-nautical usage. Both senses remain current.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Coast Guard to seize vessels that had run afoul of U.S. sanctions and laws.

From The Wall Street Journal • Apr. 18, 2026

Fox opened an investigation and concluded that Martin had run afoul of a rule of professional conduct that forbids attorneys from violating their oath of office, which includes a vow to support the U.S.

From Slate • Mar. 11, 2026

He had run afoul of the Federal Communications Commission’s regulations on broadcast content.

From Los Angeles Times • Dec. 16, 2025

According to internal records reviewed by the Washington Post, NPS employees were directed to report items that might run afoul of new regulations for review by last week.

From Salon • Jul. 31, 2025

He was arguing that Dr. Strayer’s testimony would run afoul of a rule preventing him from suggesting a legal conclusion to the jury.

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023