[ ruhn-in ]
/ ˈrʌnˌɪn /


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


Printing. added to a text without indenting.



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Origin of run-in

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

Definition for run in (2 of 2)

Origin of run

before 900; (v.) Middle English rinnen, rennen, partly < Old Norse rinna, renna, partly continuing Old English rinnan; cognate with German rinnen; form run orig. past participle, later extended to present tense; (noun and adj.) derivative of the v.

OTHER WORDS FROM run Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for run in (1 of 2)

run in

verb (adverb)

to run (an engine) gently, usually for a specified period when it is new, in order that the running surfaces may become polished
(tr) to insert or include
(intr) (of an aircraft) to approach a point or target
(tr) informal to take into custody; arresthe was run in for assault

noun run-in

British Dictionary definitions for run in (2 of 2)

/ (rʌn) /

verb runs, running, ran or run


Word Origin for run

Old English runnen, past participle of (ge) rinnan; related to Old Frisian, Old Norse rinna, Old Saxon, Gothic, Old High German rinnan
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Idioms and Phrases with run in (1 of 2)

run in


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


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.


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]


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


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

Idioms and Phrases with run in (2 of 2)


The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.