cyamellone

from The Century Dictionary.

• noun A tribasic acid, C₉H₃N₁₃, known only in solution and in its salts. The potassium salt is obtained by heating mellone with a solution of potassium hydroxid. Also called mellone hydrid.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem) A complex derivative of cyanogen, regarded as an acid, and known chiefly in its salts; -- called also hydromellonic acid.