noun, counter
Refers to the cylindrical chamber in an engine where fuel is burned. Also used as a counter for cylinders (e.g., 4気筒エンジン).
この車は6気筒エンジンを搭載している。
This car is equipped with a 6-cylinder engine.
単気筒のバイクは軽くて扱いやすい。
Single-cylinder motorcycles are light and easy to handle.