1 of 2


: someone or something that fills in

fill in

2 of 2


filled in; filling in; fills in

transitive verb

: to enrich (something, such as a design) with detail
: to give necessary or recently acquired information to
I'll fill you in

intransitive verb

: to fill a vacancy usually temporarily
interns filled in for regular staffers

Example Sentences

Verb my friend quickly filled me in on the portion of the movie that I had missed she's only filling in while the regular secretary is on vacation
Recent Examples on the Web
Faced with state claim processes that often don't get results, many organizations such as Arise Chicago have stepped in to fill in the gaps, connecting victims of wage theft with attorneys who will take their cases to court. Chris Hacker, Ash-har Quraishi, Amy Corral, CBS News, 24 Jan. 2023 Five years ago, Noora Niasari asked her mother to write a memoir in order to fill in the gaps of some fuzzy childhood memories. Manori Ravindran, Variety, 19 Jan. 2023 What’s more, the dearth of detail surrounding the shooting has led some residents to fill in the gaps themselves, causing rumors and speculation to proliferate online. Michael Brice-saddler, Washington Post, 18 Jan. 2023 Then, in a remarkable move to turn these first approximation studies into data that government agencies would actually use, the researchers called on the officials themselves to help fill in the data gaps. Rosanna Xiastaff Writer, Los Angeles Times, 17 Jan. 2023 Ghostwriters will also need to interview you to fill in any gaps. Henry Devries, Forbes, 2 Jan. 2023 Very little is known about underwater volcanoes when compared to their terrestrial counterparts, and the innovative research helped fill in some gaps. Danielle Hall, Smithsonian Magazine, 20 Dec. 2022 Many Chinese are now confronting the specter of a massive Covid outbreak that could stretch through the winter, and have been forced to improvise to fill in the gaps. Tiffany May, New York Times, 20 Dec. 2022 Many Chinese are now confronting the specter of a massive COVID outbreak that could stretch through the winter, and have been forced to improvise to fill in the gaps. David Pierson,, 20 Dec. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fill-in.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

First Known Use


1917, in the meaning defined above


1840, in the meaning defined at transitive sense 1

Time Traveler
The first known use of fill-in was in 1840

Dictionary Entries Near fill-in

Cite this Entry

“Fill-in.” Dictionary, Merriam-Webster, Accessed 4 Feb. 2023.

Kids Definition

fill in

: to furnish with specified information
fill in an application
filled us in on the latest news
: to fill a vacancy usually temporarily : substitute
filled in during the emergency
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