Fusel \Fu"sel\, n., Fusel oil \Fu"sel oil\ [G. fusel bad
liquor.]
(Chem.)
A hot, acrid, oily liquid, accompanying many alcoholic
liquors (as potato whisky, corn whisky, etc.), as an
undesirable ingredient, and consisting of several of the
higher alcohols and compound ethers, but mostly of amyl
alcohol; hence, amyl alcohol or a mixture of amyl alcohols.
[1913 Webster +PJC]
Define Fusel and 150,000 other terms at dictionary.net