noun
pivot of a folding fan
Refers to the small rivet or pivot point at the base of a folding fan (扇子) where the ribs are held together. The name literally means 'crab's eye', likely from its appearance.
扇子の蟹の目が緩んでしまった。
The pivot of the folding fan has come loose.
蟹の目が取れた扇子は、修理が必要だ。
A folding fan whose pivot has come off needs repair.