underground railroad underground press • underground railway · · · Info · Definitions · Characters · · underground railroad · · Text Common · · Latin · · Scripts 20 · · Length 5 · · Syllables Definitions · · · (noun) secret aid to escaping slaves that was provided by abolitionists in the years before the American Civil War. Synonyms: Underground Railroad, Underground Railway. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 g latin small letter g U+0067 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 r latin small letter r U+0072 u latin small letter u U+0075