What does 'fall out with someone' mean?

What it means: To have a serious disagreement with someone that causes a breakdown in the relationship. To "fall out" with someone is more than just an argument — it implies a lasting rupture, at least temporarily.

"They fell out over money and haven't spoken since."
"We fell out last year but we've made up now."

How serious is it? More serious than an argument, less permanent than a complete break. People who fall out can and often do reconcile.

As a noun — fallout: The consequences or negative effects of an event. "The fallout from the announcement affected the whole team." This is a separate but related use — it comes from nuclear fallout, the widespread effects of a blast.

• "We fell out" — British English, implies a rift
• "We had a falling out" — American English equivalent
• "We had a big argument" — neutral
• "We've had a row" — British, informal

Tags: phrasal verbs, relationships, arguments, British English