Found 2 items, similar to Spark plug.
English → English (WordNet) Definition: spark plug spark plug n : electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark [syn: sparking plug, plug]
English → English (gcide) Definition: Spark plug Spark plug \Spark plug\ In internal-combustion engines with electric ignition, a plug, screwed into the cylinder head, connected with the induction coil or magneto circuit on the outside, and used to produce a spark to ignite the fuel-air mixture in the engine. [Webster 1913 Suppl. +PJC]