adjective

1. not open; shut a closed door
2. covered over or enclosed a closed wagon
3. functioning independently; self-sufficient a closed economic system
4. not receptive to new or different ideas a closed mind
5. not open to further analysis or debate a closed question
6. restricted to certain individuals; exclusive a closed society
7. Math.
   1. of or pertaining to a curve with no end points
   2. of a surface whose plane sections are closed curves
   3. of a set in which an operation on pairs of its elements always produces an element of the set
   4. of a set of points containing all its limit points, as the set of points on and within a circle: complementary to an open set
8. Phonet. ending in a consonant sound: said of a syllable
9. Sports designating a stance, as of a golfer or a batter in baseball, in which the front foot is closer than the rear to an imaginary straight line, as one joining tee and green or one joining home plate and second base