run-in
Americannoun
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a quarrel; argument.
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Printing. matter that is added to a text, especially without indenting for a new paragraph.
adjective
verb
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to run (an engine) gently, usually for a specified period when it is new, in order that the running surfaces may become polished
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(tr) to insert or include
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(intr) (of an aircraft) to approach a point or target
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informal (tr) to take into custody; arrest
he was run in for assault
noun
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informal an argument or quarrel
he had a run-in with the boss yesterday
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an approach to the end of an event, etc
the run-in to the championship
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printing matter inserted in an existing paragraph
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Insert or include something extra, as in Can you run this map in with the text? [Early 1800s]
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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 .
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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]
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Visit someone briefly, as in If I have time, I'll run in to see Aunt Mary . [Second half of 1800s]
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Break something or someone in, as in Let's run in the new model on a short flight . [Early 1900s] Also see run into .
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
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
In his 2025 memoir, “Truly,” Richie recounted a chance run-in with the comedian George Burns at the Polo Lounge.
From The Wall Street Journal ● Sep. 16, 2026
Trump and Cohen broke the ice during a “brief yet significant” run-in at one of Trump’s golf clubs last summer, the New York Times reported.
From Slate ● Aug. 24, 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
A long time ago Mr. MacMahon had a bad run-in with a horse hisself.
From "Elijah of Buxton" by Christopher Paul Curtis
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Also see: The 10-year Treasury is having its worst run in over 100 years.
From MarketWatch ● Sep. 19, 2026
Barrio Athletics had planned to start and end their run in tiny Leimert Plaza Park while also setting up a DJ and smoothie stand there.
From Los Angeles Times ● Sep. 18, 2026
Beesley, a documentary filmmaker and avid catfish noodler, had taken a shine to Walters during Mudcats’ run in 2012 and 2013.
From Slate ● Sep. 17, 2026
The bill initially looked like a home run in the House, too.
From The Wall Street Journal ● Sep. 16, 2026
Dr. Howard explained that a “genetic factor” means that vitiligo can sometimes run in families.
From "How to Disappear Completely" by Ali Standish
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.