1
a
: not open
b
c
: composed entirely of closed tubes or vessels
a closed circulatory system
2
a
: having the skin intact with no underlying tissue exposed
closed wounds
see also closed fracture
b
of a head injury : having the skull intact : not marked by fracture or penetration of the skull
3
a
: forming a self-contained unit allowing no additions
closed association
b(1)
: traced by a moving point that returns to an arbitrary starting point
closed curve
also : so formed that every plane section is a closed curve
closed surface
(2)
: characterized by mathematical elements that when subjected to an operation produce only elements of the same set
the set of whole numbers is closed under addition and multiplication
(3)
: containing all the limit points of every possible subset
a closed interval contains its endpoints
c
: characterized by continuous return and reuse of the working substance
a closed cooling system
d
of a racecourse : having the same starting and finishing point
4
a
: confined to a few
closed membership
b
: excluding participation of outsiders or witnesses : conducted in strict secrecy
c
: rigidly excluding outside influence
a closed mind
5
: ending in a consonant
closed syllable

Examples of closed in a Sentence

He looked at me through half-closed eyes. The store is closed for lunch between 1 and 2 p.m. The beach is closed this time of night. These restrooms are closed for cleaning. The chairman declared the discussion closed and allowed no further speeches.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
More than 300 full and non-voting delegates of the powerful Central Committee will gather in Beijing for the closed-door plenum, one of seven meetings typically held within five years, between party congresses. Simone McCarthy, CNN Money, 20 Oct. 2025 However, during the shutdown, VA benefits regional offices are closed, transition program assistance has ceased and VA cemetery grounds are not being maintained. Zac Anderson, USA Today, 19 Oct. 2025 These games, previously played as closed-door scrimmages without media, cheerleaders or fans, have often served as an inverse predictor of the coming season. Mark Zeigler, San Diego Union-Tribune, 19 Oct. 2025 Never leave gas cans in a closed vehicle to avoid the buildup of gas vapors. Kamron Sanders, Better Homes & Gardens, 19 Oct. 2025 See All Example Sentences for closed

Word History

First Known Use

13th century, in the meaning defined at sense 1a

Time Traveler
The first known use of closed was in the 13th century

Browse Nearby Words

Cite this Entry

“Closed.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/closed. Accessed 21 Oct. 2025.

Kids Definition

closed

adjective
1
a
: not open : enclosed
b
: made up entirely of closed tubes or vessels
a closed circulatory system
2
: formed by a line that returns to its starting point
a closed curve
3
: having elements that when a mathematical operation (as addition) is performed on them produce only other elements of the same set
the set of whole numbers is closed under addition
4
: not admitting or not easily admitting new members
a closed meeting
a closed society

Medical Definition

closed

adjective
1
: being a complete self-contained system with nothing transferred in or out
a closed thermodynamic system
2
a
: having the skin intact with no underlying tissue exposed
closed wounds
see closed fracture
b
of a head injury : having the skull intact : not marked by fracture or penetration of the skull
Closed head injuries result from the force of a blast or a blow in which the skull remains intact but the brain, surrounded by fluid like an egg yolk, gets wrenched or slammed against the skull wall.Neil Shea
3
: not discharging pathogenic organisms to the outside
a case of closed tuberculosis
compare open entry 1 sense 2

Legal Definition

closed

adjective
1
: confined to a few
closed membership
2
: excluding outsiders or witnesses : conducted in secrecy
closed hearings

More from Merriam-Webster on closed

Last Updated: - Updated example sentences
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