: someone or something that fills in
She performed well as the emergency fill-in.
filled in; filling in; fills in
1
: to enrich (something, such as a design) with detail
2
: to give necessary or recently acquired information to
I'll fill you in
: to fill a vacancy usually temporarily
Interns filled in for regular staffers.
Examples of fill-in in a Sentence
Noun
I'm just a fill-in, so I have no idea where office supplies are kept
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
CBS News, 28 Dec. 2025
Brown has been a valuable fill-in as a backup at guard and center this season, starting two games in place of rookie Jared Wilson at left guard.
—Doug Kyed, Boston Herald, 23 Dec. 2025
Senior Editor, Los Angeles Times, 2 Jan. 2026
Part of my annual resolution is to devote each summer to filling in a major blind spot.
—Robert Rubsam, The Atlantic, 1 Jan. 2026
See All Example Sentences for fill-in
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Noun
Rookie Mohamed Diawara of France was the fill-in starter for Hart.
—CBS News, 28 Dec. 2025
Brown has been a valuable fill-in as a backup at guard and center this season, starting two games in place of rookie Jared Wilson at left guard.
—Doug Kyed, Boston Herald, 23 Dec. 2025
Verb
This is Austin Knoblauch filling in for newsletter editor Houston Mitchell.
—Senior Editor, Los Angeles Times, 2 Jan. 2026
Part of my annual resolution is to devote each summer to filling in a major blind spot.
—Robert Rubsam, The Atlantic, 1 Jan. 2026
See All Example Sentences for fill-in
Cite this Entry
“Fill-in.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fill-in. Accessed 6 Jan. 2026.
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