underpass underpartner • underpassion · · · Info · Definitions · Synonyms · Characters · · underpass · · Text Latin · · Script 9 · · Length Definitions · · · (noun) an underground tunnel or passage enabling pedestrians to cross a road or railway. Synonyms: subway. · · Noun Definition 1 Synonyms · · · subway · · Synonym 1 Characters · · a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 n latin small letter n U+006E 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