a.

1. 关闭的；封闭的；闭合的
   a closed door

   关着的门

2. 关闭排外的；不接受新思想的；自给自足的
   a closed mind

   闭塞僵死的思想

   a closed economic system

   自给自足的经济体系

3. （会社成员等）只限于少数人的
   a closed membership

   只限少数人的会员资格

4. 不公开的，保密的
   a closed file on suspects

   嫌疑犯机密档案

5. 了结的，已定局的
   a closed question

   已了结的问题

6. 【数】闭的
7. 【语】闭音节的
8. 【体】（击高尔夫球等时的姿势）闭式的，前身微后转的

adj.

1. not open or allowing access.
   ▸not open to all:

   the UN Security Council met in closed session.
2. not communicating with or influenced by others:
   a closed society.
3. Mathematics  (of a set) having the property that the result of a specified operation on any element of the set is itself a member of the set.
4. Geometry  (of a curve or figure) formed from a single unbroken line.
5. Phonetics  (of a syllable) ending in a consonant.