noun
Standard automotive term for the ignition component.
エンジンの調子が悪いので、点火プラグを交換した。
The engine was running rough, so I replaced the spark plugs.
Synonymous loanword from English; 点火プラグ is the more common Japanese term.
Compound of 点火 (ignition) and プラグ (plug), a straightforward technical term.