from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An acrid, oily, poisonous liquid mixture of amyl alcohols, occurring in incompletely distilled alcoholic liquids and used as a solvent and in the manufacture of explosives and pure amyl alcohols.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A mixture of several higher-order alcohols (alcohols with more than two carbon atoms) formed as byproduct in the normal fermentation process. An excessive concentration, as in low-quality moonshine, causes unpleasant taste.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a mixture of amyl alcohols and propanol and butanol formed from distillation of fermented liquors
German Fusel, bad liquor, from Low German.(American Heritage® Dictionary of the English Language, Fourth Edition)
The word "fusel" comes from German Fusel, which is used to refer to low-quality alcoholic beverages in general, especially to inferior wines and spirits distilled with inadequate equipment. (Wiktionary)