Main Entry: closed

Pronunciation: \ˈklōzd\

Function: adjective

Date: 13th century

1 a : not open b : enclosed c : composed entirely of closed tubes or vessels <a closed circulatory system>
2 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
3 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>
4 : ending in a consonant <closed syllable>