What does indoor mean?
Indoor is an adjective describing something located, performed, or intended for use inside a building or other enclosed space. It contrasts with “outdoor,” and the related adverb is “indoors.” The word is common in expressions such as “indoor sports,” “indoor plants,” “indoor lighting,” and “indoor accommodation.” Its use can suggest not merely a physical location but also a degree of protection, comfort, or controlled conditions, although this depends on the context. For example, indoor sports may take place in a specially designed facility, while indoor plants are cultivated away from natural outdoor conditions. The expression can also describe activities that normally happen outside but have been moved into a building. Etymologically, indoor combines “in” with “door,” reflecting its literal sense of being or happening within a doorway or enclosed interior. It is a useful everyday word for distinguishing indoor environments and activities from those associated with the open air.
adjectiveSituated or carried out inside a building or other enclosed space. It can also mean intended for use in such places.
- Located or occurring inside a building or enclosed space.
- Designed or intended for use inside a building rather than outdoors.
"The museum offers a fascinating tour of its indoor garden."
"The event was moved indoors because of the heavy rain."
"The shelter provides indoor accommodation for families during the winter."
The word indoor literally means “within the door,” turning an everyday architectural feature into a description of everything protected from the outside world.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does indoor come from?
The word indoor was formed in English from the preposition “in” and the noun “door.” Its literal history is therefore the idea of being “within the door” or inside an enclosed space. The related adverb indoors developed alongside the adjective and is now more common when referring to an activity or location in general.
Related word forms
How indoor is actually used
Usually used before a noun, as in “indoor sports” or “an indoor market.” The adverb form is “indoors,” as in “We stayed indoors all afternoon.”