[ 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.

Nearby words

  1. run up,
  2. run wild,
  3. run with,
  4. run-down,
  5. run-flat,
  6. run-of-paper,
  7. run-of-the-mill,
  8. run-of-the-mine,
  9. run-on,
  10. run-on sentence

Origin of run-in

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

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.

Related forms Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for run in

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


/ (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

Word Origin and History for run in
Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with run in

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.


In addition to the idioms beginning with run

  • run across
  • run a fever
  • run afoul of
  • run after
  • run against
  • run along
  • run amok
  • run an errand
  • run a risk
  • run around
  • run around in circles
  • run around like a chicken
  • run around with
  • run a temperature
  • run a tight ship
  • run away
  • run away with
  • run by someone
  • run circles around
  • run counter to
  • run down
  • run dry
  • run for it
  • run for one's money, a
  • run foul
  • run high
  • run in
  • run in place
  • run interference
  • run in the blood
  • run into
  • run into a stone wall
  • run into the ground
  • run its course
  • run like clockwork
  • running on empty
  • running start
  • run off
  • run off at the mouth
  • run off with
  • run of luck
  • run of the mill
  • run on
  • run one ragged
  • run one's eyes over
  • run one's head against the wall
  • run one's own show
  • run out
  • run out of
  • run out on
  • run over
  • run rings around
  • run riot
  • run scared
  • run short
  • run someone in
  • run someone off his or her feet
  • run the gamut
  • run the gauntlet
  • run the show
  • run through
  • run to
  • run to earth
  • run to form
  • run to seed
  • run up
  • run wild
  • run with

also see:

  • beat (run) one's head against the wall
  • cut and run
  • dry run
  • eat and run
  • end run
  • go (run) around in circles
  • great minds (run in the same channel)
  • home run
  • in the long run
  • like clockwork, run
  • make a break (run) for
  • make one's blood run cold
  • (run) off someone's feet
  • on the run
  • still waters run deep
  • tight ship, run a
  • well's run dry

Also see underrunning.

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