Akademik

closed
adj.
1 not giving access; shut.
2 (of a shop etc.) having ceased business temporarily.
3 (of a society, system, etc.) self-contained; not communicating with others.
4 (of a sport etc.) restricted to specified competitors etc.
Phrases and idioms:
closed book see BOOK. closed-circuit (of television) transmitted by wires to a restricted set of receivers. closed-end having a predetermined extent (cf. open-ended). closed season US = close season (see CLOSE(1)). closed shop
1 a place of work etc. where all employees must belong to an agreed trade union.
2 this system. closed syllable a syllable ending in a consonant.

Useful english dictionary. 2012.