fill-in
noun
a person or thing that fills in, as a substitute, replacement, or insertion.
fill-in
American
[fil-in]
/ ˈfɪlˌɪn /
noun
-
fill-ins
plural
-
a person or thing that fills in, as a substitute, replacement, or insertion.
The company used a fill-in for workers on vacation.
-
a brief, informative summary; a rundown.
fill in
British
verb
-
(tr) to complete (a form, drawing, etc)
-
(intr) to act as a substitute
a girl is filling in while the typist is away
-
(tr) to put material into (a hole or cavity), esp so as to make it level with a surface
-
informal (tr) to inform with facts or news
-
slang (tr) to attack and injure severely
noun
-
a substitute
-
informal a briefing to complete one's understanding
fill in
Idioms
-
Complete something, especially by supplying more information or detail. For example, Be sure to fill in your salary history . It is also put as fill in the blanks , as in We'll rely on Mary to fill in the blanks . Yet another related usage is fill someone in , as in I couldn't attend, so will you fill me in? The first term dates from the mid-1800s; the others from the first half of the 1900s. Also see fill out .
-
Also, fill in for . Take someone's place, substitute for. For example, The understudy had to fill in at the last minute , or I can't come but my wife will fill in for me . Also see fill someone's shoes .
Other Word Forms
Noun Inflected Forms
Etymology
Origin of fill-in
First recorded in 1915–20; noun use of verb phrase fill in
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 this entertaining action film, the actor plays a Midwestern town’s fill-in lawman, who faces an unexpected threat from the East.
From The Wall Street Journal ● Aug. 13, 2026
When their All-Star forward Jalen Williams suffered a hamstring injury, they had an appropriate fill-in to call upon: a backup big man named, coincidentally, Jaylin Williams.
From The Wall Street Journal ● May 7, 2026
She is a frequent fill-in for “CBS Mornings” co-host Gayle King.
From Los Angeles Times ● Jan. 9, 2026
She appeared regularly on cable ratings leader Fox News since 2013, appearing as a guest co-host on “The Five” and a fill-in host on its prime-time programs.
From Los Angeles Times ● Dec. 15, 2025
This one was a last-minute fill-in for a famous violinist who’d gone down with the flu.
From "Goodbye Stranger" by Rebecca Stead
Guy Mowbray: The exits of Youri Tielemans and Morgan Rogers have left a big gap to fill in Aston Villa's midfield.
From BBC ● Aug. 18, 2026
America’s fuel-makers are maxed out as they try to fill in the gaps of the global fuel supply crunch.
From The Wall Street Journal ● Aug. 7, 2026
We fill in the backstory of his narrative.
From Los Angeles Times ● Aug. 6, 2026
“I’ve always had this void. There’s this space I’d like to fill in my life,” Samson said.
From MarketWatch ● Jul. 24, 2026
Ella tried to resist gazing into the dark waters or letting her imagination fill in what could be lurking down there.
From "The Marvellers" by Dhonielle Clayton
So last winter they felt comfortable trading Mark Delgado and Gastón Brugman, the two most likely fill-ins for Puig, largely to fit their payroll under the MLS salary cap.
From Los Angeles Times ● Jan. 6, 2026
Maxwell noted that his work had been covered by knowledgeable fill-ins from out of state.
From Salon ● Jul. 24, 2025
In one sense, Stewart is the latest in a line of celebrity fill-ins who have hosted “The Daily Show” since Trevor Noah left in December 2022.
From New York Times ● Feb. 13, 2024
McAvoy was one of three regulars on the blue line that the Bruins didn’t have, making the performance of fill-ins like rookie Lohrei even more impressive.
From Washington Times ● Nov. 3, 2023
The conga drum player was especially wild, playing insane fill-ins all over the place.
From "Drums, Girls, and Dangerous Pie" by Jordan Sonnenblick
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.
