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

The police acted on a suspect description given to police in 2010 by the roommate of one victim, Amber Costello, after she had a run-in with a client.

From BBC • Apr. 8, 2026

Similarly, the warmer temperatures have compelled outdoor enthusiasts to hit the trails, increasing the odds of a run-in with the serpents.

From Los Angeles Times • Apr. 1, 2026

With this police run-in, Country Joe and the Fish received a slew of press, riling up the public ahead of their Woodstock performance.

From Los Angeles Times • Mar. 8, 2026

And Falkirk are all but assured the final available top-six place and would probably host Hearts during the run-in.

From BBC • Feb. 28, 2026

Her eyes landed on the red Talent bracelet around her wrist, now sticky with glue-water from its run-in with the dish towel.

From "A Tangle of Knots" by Lisa Graff

Related Words

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