riser pipe riser main • riser pipeline · · · Info · Definitions · Synonyms · Characters · · riser pipe · · Text Common · · Latin · · Scripts 10 · · Length 3 · · Syllables Definitions · · · (noun) a vertical pipe in a building. Synonyms: riser, riser pipe, riser pipeline, riser main. · · Noun Definition 1 Synonyms · · · riser · · Synonym 1 riser pipeline · · Synonym 2 riser main · · Synonym 3 Characters · · space U+0020 e latin small letter e U+0065 i latin small letter i U+0069 p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073