This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 帠 is uncertain. It visually combines 臼 (mortar) on top and 巾 (cloth) on the bottom, but the original meaning and component relationship are unclear.
Since the meaning is unclear, picture a mortar (臼) resting on a cloth (巾) as a mysterious object whose purpose is unknown.
For ゲイ, imagine a gate (ゲイ sounds like 'gate') made of a mortar and cloth: a strange gate that leads to an uncertain meaning.