Definition of closed
1a : not openb : enclosedc : composed entirely of closed tubes or vessels <a closed circulatory system>
2a : 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
3a : confined to a few <closed membership>b : excluding participation of outsiders or witnesses : conducted in strict secrecyc : rigidly excluding outside influence <a closed mind>
4 : 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.
First Known Use of closed
CLOSED Defined for English Language Learners
Definition of closed for English Language Learners
: covering an opening : having an opening that is covered
: not operating or open to the public
: having ended : not being worked on anymore
CLOSED Defined for Kids
Definition of closed for Students
: not open <a closed door>
Medical Definition of closed
1: being a complete self-contained system with nothing transferred in or out <a closed thermodynamic system>
2a: covered by unbroken skin <a closed fracture>b: not penetrating 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, National Geographic, December 2006>
3: not discharging pathogenic organisms to the outside <a case of closed tuberculosis>—compare open 2
Legal Definition of closed
1 : confined to a few <closed membership>
2 : excluding outsiders or witnesses : conducted in secrecy <closed hearings>
Seen and Heard
What made you want to look up closed? Please tell us where you read or heard it (including the quote, if possible).