methanal methadone • methanate · · · Info · Definitions · Synonyms · Characters · · methanal · · Text Latin · · Script 8 · · Length Definitions · · · (noun) a colorless poisonous gas; made by the oxidation of methanol. Synonyms: formaldehyde. · · Noun Definition 1 Synonyms · · · formaldehyde · · Synonym 1 Characters · · a latin small letter a U+0061 e latin small letter e U+0065 h latin small letter h U+0068 l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E t latin small letter t U+0074