curtain; field headquarters; secret meeting place
Archaic/literary term for a curtain or tent used as a military command post or for secret meetings. In modern Japanese, 幕 (まく) or カーテン are used for 'curtain', and 司令部 for 'headquarters'.
In old war tales, scenes often appear where the general sets up a curtained enclosure and holds a war council.
The word 帷幕 is hardly used in modern times.
Compound of 帷 (い, 'curtain') and 幕 (ばく, 'curtain/tent'). The exact historical derivation is uncertain; the spelling is conventionally associated with military command tents and secret meetings in classical Chinese and Japanese literature.