- The definition of a fill-in is a person or thing that is a substitute for someone or something else.
An example of fill-in is a substitute teacher.
fill-in definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a person or thing that fills a vacancy or gap, often temporarily
fill-in definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
- One that serves as a substitute for another.
- A short informative summary.
fill-in - Phrases/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.