noun
General term for an electrical plug or connector. Used for power plugs, audio jacks, and similar connecting devices.
コンセントにプラグを差し込んでください。
Please insert the plug into the outlet.
このプラグはUSBポートに合わない。
This plug doesn't fit the USB port.
noun
Specifically refers to a spark plug in an engine. Often used in automotive contexts.
エンジンの調子が悪いので、プラグを交換した。
The engine was running rough, so I replaced the spark plugs.