Here you will find one or more explanations in English for the word Spark plug.
Also in the bottom left of the page several parts of wikipedia pages related to the word Spark plug and, of course, Spark plug synonyms and on the right images related to the word Spark plug.
Spark plug
Spark plug Spark plug
In internal-combustion engines with electric ignition, a
plug, screwed into the cylinder head, having through it an
insulated wire which is connected with the induction coil or
magneto circuit on the outside, and forms, with another
terminal on the base of the plug, a spark gap inside the
cylinder.
Meaning of Spark plug from wikipedia