spark plug spark off • spark potential · · · Info · Definitions · Synonyms · Characters · · spark plug · · Text Common · · Latin · · Scripts 10 · · Length 2 · · Syllables Definitions · · · (noun) electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark. Synonyms: spark plug, sparking plug, plug. · · Noun Definition 1 Synonyms · · · sparking plug · · Synonym 1 plug · · Synonym 2 Characters · · space U+0020 a latin small letter a U+0061 g latin small letter g U+0067 k latin small letter k U+006B l latin small letter l U+006C p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073 u latin small letter u U+0075