perforated coin; coin with a hole
Historical term for coins with a central hole, such as old Chinese-style cash coins or early Japanese coins.
I saw Edo-period perforated coins at the museum.
Compound of 穴 (あな, 'hole') and 銭 (せん, 'coin'). The exact historical derivation is uncertain, but the term straightforwardly describes coins with a central perforation.