'Spark plug' definitions:

Definition of 'spark plug'

(from WordNet)
noun
Electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark [syn: spark plug, sparking plug, plug]

Definition of 'Spark plug'

From: GCIDE
  • 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]

Words containing 'Spark plug'