carbon dioxide carbon dichloride • carbon-dioxide recorder · · · Info · Definitions · Synonyms · Characters · · carbon dioxide · · Text Common · · Latin · · Scripts 14 · · Length Definitions · · · (noun) a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis. Synonyms: CO2, carbonic acid gas. · · Noun Definition 1 Synonyms · · · carbon · · Synonym 1 c · · Synonym 2 atomic number 6 · · Synonym 3 carbon paper · · Synonym 4 carbon copy · · Synonym 5 Characters · · space U+0020 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 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 x latin small letter x U+0078