fusel oil

noun

1. a mixture consisting chiefly of amyl alcohols obtained as a by-product in the fermentation of grains.

noun

1. a mixture of amyl alcohols, propanol, and butanol: a by-product in the distillation of fermented liquors used as a source of amyl alcohols

1. An acrid, oily, poisonous liquid occurring in the distillation products of fermented alcoholic liquids. Fusel oil is a mixture of amyl alcohols, fatty acids, and esters. It is used in paints, plastics, and varnishes, and in the manufacture of explosives.