English dictionary, thesaurus, translations & etymology
FreeDict.com
adjective A2 Elementary Common

indoor

IHN-daw

Indoor (adjective) means located, used, or done inside a building. Example: “They installed an indoor pool for winter use.”

adjective
1
Located, used, or done inside a building.
"They installed an indoor pool for winter use."
"Indoor plants need less direct sunlight than outdoor ones."

How to Use Indoor

Learner’s notes

In plain EnglishHappening or existing inside a building, not outside.

Common mistake

"Indoor" is the adjective (an indoor pool); "indoors" is the adverb (stay indoors).

Easily confused with
Study it as flashcards or scroll it in Flow — saved to your collection.
Test yourself on “indoor” A quick quiz — meaning, synonyms & usage

Fill the Gap

Can you complete this real example?

They installed an _____ pool for winter use.

Etymology

From "(with)in" plus "door," first recorded in 1711.

· First attested 1711

Class of 1711 indoor joined the language around 1711.
See the full Class of 1711 →

Related Words

Rhymes for indoor

See all rhymes for indoor →

Frequently Asked Questions

What does “indoor” mean?

The word “indoor” means located, used, or done inside a building. In plain terms, happening or existing inside a building, not outside.

How do you pronounce “indoor”?

“Indoor” is pronounced IHN-daw (/ˈɪndoɹ/ in IPA).

How do you use “indoor” in a sentence?

Here is “indoor” used in a sentence: “They installed an indoor pool for winter use.”

What part of speech is “indoor”?

“Indoor” is an adjective.

Where does the word “indoor” come from?

The word “indoor” dates back to around 1711. From "(with)in" plus "door," first recorded in 1711.

Is “indoor” a common word?

“Indoor” is a fairly common word in modern English, usually learned at around the A2 level.

What is the difference between indoor and indoors?

Indoor is an adjective that goes before a noun — an indoor pool, indoor plants — while indoors is an adverb meaning inside a building: 'we stayed indoors'. They are not interchangeable: 'an indoors pool' and 'we stayed indoor' are both incorrect.

Can you say 'the pool is indoor'?

No — indoor is an attributive adjective, which means it is used before a noun, as in 'an indoor pool'. After a verb, English uses the adverb indoors or a phrase like 'inside': 'the pool is indoors' or 'the pool is inside the building'.

What is the opposite of indoor?

The direct opposite is outdoor, used the same way before a noun: outdoor seating, an outdoor concert. The matching adverb pair is indoors and outdoors: 'children should play outdoors as well as indoors'.

People Also Searched

Definitions: FreeDict original editorial