formaldehyde formalazine • formaldehydesulphoxylate · · · Info · Definitions · Synonyms · Characters · · formaldehyde · · Text Latin · · Script 12 · · Length Definitions · · · (noun) a colorless poisonous gas; made by the oxidation of methanol. Synonyms: methanal. · · Noun Definition 1 Synonyms · · · methanal · · Synonym 1 Characters · · a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 f latin small letter f U+0066 h latin small letter h U+0068 l latin small letter l U+006C m latin small letter m U+006D o latin small letter o U+006F r latin small letter r U+0072 y latin small letter y U+0079