opening/closing device; mechanical opener/closer
Refers to a mechanical device that opens and closes something, such as shutters, gates, or windows. Often used in technical or product contexts.
This shutter is equipped with an automatic opening/closing device.
The window opener/closer is broken and won't move.
Compound of 開閉 (opening and closing) + 機 (machine, device). The exact historical derivation is uncertain, but the word follows a common pattern for naming mechanical devices.