closed

1 of 2

adjective

ˈklōzd 

1

a

: not open

b

: enclosed

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

closed

2 of 2

past tense and past participle of close entry 1

Examples of closed in a Sentence

Adjective

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

Adjective

Main Street, Sixth Street, Eighth Street, Railroad Avenue and Newhall Avenue are all closed. — Chelsea Hylton, CBS News, 24 Aug. 2026

Rezaei, who is an adviser to Iran’s supreme leader, Mojtaba Khamanei, said Iran will not yield to US pressure, adding the Strait of Hormuz will remain closed until Washington meets its commitments. — Tim Lister, CNN Money, 23 Aug. 2026

Many of the area’s most popular hiking and camping areas, including Andrew Molera State Park, Pfeiffer Big Sur State Park and Julia Pfeiffer Burns State Park, remain closed as of Sunday, a California State Parks update said. — Roger Vincent, Los Angeles Times, 22 Aug. 2026

Officials said the railroad crossing will remain closed while repairs are completed, which could take up to two weeks. — Lillie Davidson, Fort Worth Star-Telegram, 21 Aug. 2026

Word History

First Known Use

Adjective

14th century, in the meaning defined at sense 1b

Phrases Containing closed

• a closed book
• behind closed doors
• closed book
• closed-captioned
• closed-captioning
• closed-cell
• closed cell foam
• closed-circuit
• closed-circuit television
• closed comedo
• closed corporation
• closed couplet
• closed-door
• closed-end
• closed fracture
• closed loop
• closed-minded
• closed session
• closed shop
• closed stance
• meet in closed session
• simple closed curve
• with one's eyes shut/closed

Rhymes for closed

• apposed
• bulldozed
• composed
• deposed
• disclosed
• disposed
• enclosed
• exposed
• foreclosed
• imposed
• inclosed
• opposed

Kids Definition

closed

adjective

ˈklōzd 

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

ˈklōzd 

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