enan·thal·de·hyde noun oroe·nan·thal·de·hyde\ˌēˌnanˈthaldəˌhīd\ Etymology: International Scientific Vocabulary enanth-, oenanth- (as in enanthic acid) + aldehyde : a pungent oily compound CH3(CH2)5CHO obtained by pyrolysis of castor oil and used especially in making artificial cognac — called also heptaldehyde, heptanal