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.
Some indoor farms do not have bees, and growers pay workers to pollinate flowers by hand.
From Los Angeles Times ● Aug. 27, 2026
A second possibility is to redesign indoor lighting so that it better reproduces the wavelengths present outdoors.
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
LONDON—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
On her right shin, visible even in the dimness of the indoor light, a thin pink scar jags down from her knee.
From "Girl in the Blue Coat" by Monica Hesse
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.
