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indoor

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.

Definitions of indoor
  1. adjective
    located, suited for, or taking place within a building
    indoor activities for a rainy day”
    “an indoor pool”
    Synonyms:
    interior
    situated within or suitable for inside a building
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    Antonyms:
    out-of-door, outdoor, outside
    located, suited for, or taking place in the open air
    exterior
    situated in or suitable for the outdoors or outside of a building
    alfresco, open-air
    in the open air
    outdoorsy
    characteristic of or suitable to outdoor life
    show more antonyms...
  2. adjective
    within doors
    “an indoor setting”
    Synonyms:
    interior
    situated within or suitable for inside a building
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