closed

adjective \ˈklōzd\

: covering an opening : having an opening that is covered

: not operating or open to the public

: having ended : not being worked on anymore

Full Definition of CLOSED

a : not open

b : enclosed

c : composed entirely of closed tubes or vessels <a closed circulatory system>

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

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>

: ending in a consonant <closed syllable>

See closed defined for English-language learners

See closed defined for kids