indoor
Americanadjective
adjective
Etymology
Origin of indoor
1705–15; aphetic variant of within-door, originally phrase within ( the ) door, i.e., inside the house
Explanation
Use the adjective indoor to describe something that happens or is used inside a building or house. Your indoor furniture is probably a little fancier than your plastic outdoor furniture. Indoor sports are the ones you play inside, like ping pong and floor hockey — beach volleyball is not an indoor sport. Your indoor voice is likewise the one you use in your house or classroom, a quieter voice than when you holler across a parking lot to your friend in his convertible. Indoor, which has been used since the 18th century, is a shortened form of the phrase within door.
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.
New research led by scientists at Cincinnati Children's and the University of Alabama at Birmingham points to indoor lighting as a possible way to reduce that risk.
From Science Daily ● Aug. 26, 2026
Its revitalized city center features the Frederik Meijer Gardens & Sculpture Park, which boasts 158 acres of indoor and outdoor botanic gardens, nature trails and a massive sculpture collection.
From MarketWatch ● Aug. 25, 2026
In Britain, a night at the pub doesn’t require a table, a chair or even indoor shelter.
From The Wall Street Journal ● Aug. 18, 2026
The LSU graduate wanted to play indoor volleyball in college, but she couldn’t because of injuries and instead joined the beach volleyball team.
From Los Angeles Times ● Aug. 16, 2026
Ben’s not shy about using cheat codes for money, so we’ve got a huge indoor pool and a sunroom for parties.
From "What If It's Us" by Becky Albertalli and Adam Silvera
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.
