nitrogen dioxide nitrogen cycle • nitrogen equilibrium · · · Info · Definitions · Synonyms · Characters · · nitrogen dioxide · · Text Common · · Latin · · Scripts 16 · · Length Definitions · · · (noun) a highly poisonous brown gas (NO2). · · Noun Definition 1 Synonyms · · · nitrogen · · Synonym 1 n · · Synonym 2 atomic number 7 · · Synonym 3 Characters · · space U+0020 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 n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 t latin small letter t U+0074 x latin small letter x U+0078