fall foul of(redirected from run foul of someone or something)
fall (a)foul of someone or somethingand run (a)foul of someone or something
to get into a situation where one is opposed to someone or something; to get into trouble with someone or something. Dan fell afoul of the law at an early age. I hope that you will avoid falling afoul of the district manager. She can be a formidable enemy. I hope I don't run afoul of your sister. She doesn't like me.
fall foul of somebody
to upset someone, so that they do not like you and try to harm you Officials who fall foul of the mayor find themselves exiled to the most boring departments.
fall foul of something(slightly formal)
to break a law or a rule, and often be punished If their market share grows too large, they will fall foul of anti-monopoly laws.