telephone extension telephone exchange • telephone faultsman · · · Info · Definitions · Synonyms · Characters · · telephone extension · · Text Common · · Latin · · Scripts 19 · · Length 6 · · Syllables Definitions · · · (noun) an additional telephone set that is connected to the same telephone line. Synonyms: extension, telephone extension, extension phone. · · Noun Definition 1 Synonyms · · · extension · · Synonym 1 extension phone · · Synonym 2 Characters · · space U+0020 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 s latin small letter s U+0073 t latin small letter t U+0074 x latin small letter x U+0078