noun azulene (organic compound, uncountable) A bicyclic aromatic hydrocarbon containing a five- and a seven-membered fused ring; it is a blue, oily liquid first obtained from the essential oil of wormwood. 1
noun azulene (Uncountable Noun) (organic chemistry) A bicyclic aromatic hydrocarbon containing a five- and a seven-membered fused ring; it is a blue, oily liquid first obtained from the essential oil of wormwood. 0
noun azulene (Countable Noun) (organic chemistry) Any of its derivatives. 0
