indoor

American  

[in-dawr, -dohr] / ˈɪnˌdɔr, -ˌdoʊr /

adjective

1. occurring, used, etc., in a house or building, rather than out of doors.

   indoor games.

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indoor British  

/ ˈɪnˌdɔː /

adjective

1. of, situated in, or appropriate to the inside of a house or other building

   an indoor tennis court

   indoor amusements

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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

Indoor events will have a standby line that does not require tickets; however, there is no guarantee you will be seated.

From Los Angeles Times • Apr. 15, 2026

Following Josh Kerr's 3,000m triumph on Saturday, it guaranteed the British team's most successful World Indoor Championships of all time, surpassing the three gold medals achieved in 1999.

From BBC • Mar. 22, 2026

Belgium win a chaotic 4x400m mixed relay final at the World Indoor Athletics Championships in Poland.

From BBC • Mar. 21, 2026

On Friday, footage emerged of the smouldering and ruined 12,000-seat Azadi Indoor Stadium in Tehran.

From Barron's • Mar. 6, 2026

Indoor sandals and outdoor ones were exactly the same, except you must never get them mixed up!

From "A Place to Belong" by Cynthia Kadohata

Related Words

• private