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.
The airport remained closed as of Wednesday afternoon, police said in the latest post on social media. Eric Lagatta, USA TODAY, 20 Feb. 2025 Hazmat crews were monitoring air quality and advised all businesses within a 1-mile radius to remain closed until further notice. arkansasonline.com, 19 Feb. 2025 The runway where the plane crashed is expected to remain closed through at least Thursday evening, according to a notice issued to pilots Tuesday. Andy Rose, CNN, 18 Feb. 2025 Two runways remained closed, which Flint said may impact operations. David Brennan, ABC News, 18 Feb. 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

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Cite this Entry

“Closed.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/closed. Accessed 3 Mar. 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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