noun
exhaust port; exhaust vent; exhaust outlet
An opening through which exhaust gas or air is discharged, commonly found on vehicles, machinery, or ventilation systems.
車の排気口から白い煙が出ている。
White smoke is coming out of the car's exhaust port.
この部屋の排気口は定期的に掃除が必要だ。
The exhaust vent in this room needs regular cleaning.
吸気口 is an intake port, the opposite of 排気口.
Compound of 排気 (exhaust) + 口 (opening, mouth).