Spark plug and Wave maker

Spark plug noun - Electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark.

Wave maker and spark plug are semantically related In some cases you can use "Wave maker" instead a noun phrase "Spark plug".

Spark plug and wave maker are semantically related in catalyst topic. Sometimes you can use "Spark plug" instead a noun phrase "Wave maker", if it concerns topics such as something which incites activity.