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• run-in
  run-in

  noun

  a quarrel; argument.
• run in
  run in

  verb

  to run (an engine) gently, usually for a specified period when it is new, in order that the running surfaces may become polished

run-in

American  

[ruhn-in] / ˈrʌnˌɪn /

noun

1. a quarrel; argument.

2. Printing. matter that is added to a text, especially without indenting for a new paragraph.

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adjective

1. Printing. added to a text without indenting.

run in British  

verb

1. to run (an engine) gently, usually for a specified period when it is new, in order that the running surfaces may become polished

2. (tr) to insert or include

3. (intr) (of an aircraft) to approach a point or target

4. informal (tr) to take into custody; arrest

   he was run in for assault

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noun

1. informal an argument or quarrel

   he had a run-in with the boss yesterday

2. an approach to the end of an event, etc

   the run-in to the championship

3. printing matter inserted in an existing paragraph

run in Idioms  

1. Insert or include something extra, as in Can you run this map in with the text? [Early 1800s]

2. Also, run on . In printing, make a solid body of text without a paragraph or other break, as in The quotation should be run in rather than set as a paragraph .

3. Also, run someone in . Take someone into custody, as in The police were going to run him in, but he got away . [ Slang ; mid-1800s]

4. Visit someone briefly, as in If I have time, I'll run in to see Aunt Mary . [Second half of 1800s]

5. Break something or someone in, as in Let's run in the new model on a short flight . [Early 1900s] Also see run into .

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Etymology

Origin of run-in

First recorded in 1900–05; noun, adj. use of verb phrase run in

Explanation

A run-in is a confrontation or an argument. Peaceful protests go more smoothly when protestors avoid run-ins with the police. If you get in a fight with your brother about how he never loads the dishwasher, you can call that a run-in. A more serious kind of run-in might be a shoplifter's run-in with a store security guard or a basketball player's angry run-in with a referee that gets him benched for the rest of the season. Before 1905, run-in meant an instance of actually running somewhere.

Example Sentences

See Examples For:

run-in run in

That put heavy demands on Martin Zubimendi and Declan Rice, with the former dropping out of the side completely as the amount of work he was asked to do took its toll during the run-in.

From BBC ● Aug. 5, 2026

The LP opens with “Casablanca,” in which she recounts a run-in with the Grateful Dead’s Bob Weir in New Orleans in the late ’80s.

From Los Angeles Times ● Aug. 4, 2026

After a rough start, including a run-in with an irritating policeman, she lands at the home of a baker, Osono, who gives her a place to stay in exchange for labor and her delivery services.

From Salon ● Jul. 30, 2026

I figured a quarter-million miles was an outside chance, but my run-in with Tightsqueeze McHalfmill has given me confidence.

From Barron's ● May 29, 2026

I didn’t say anything, as I was still pondering my run-in with Sister Redempta.

From "Moon Over Manifest" by Clare Vanderpool

"And while it's true that osteoarthritis can run in families, it doesn't mean there's nothing a person can do to successfully lower their risk of developing it."

From Science Daily ● Aug. 20, 2026

Walmart sells ads that run in its digital channels and stores.

From The Wall Street Journal ● Aug. 20, 2026

It’s about how well we’re going to be constructed for October and a deeper run in the playoffs.

From Los Angeles Times ● Aug. 16, 2026

After a long winning run in 2025, England flopped in the Six Nations earlier this year, winning just one match, but recovered to win two out of their three Nations Championship games in July.

From BBC ● Aug. 12, 2026

I turn and run in the opposite direction until I’m back at the center of the rear of the ship.

From "The Last Cuentista" by Donna Barba Higuera

Related Words

• altercation
• confrontation
• falling-out
• quarrel
• skirmish
• tussle