A colorless, volatile, flammable liquid produced by the fermentation of certain types of grain, fruit, or wood pulp. Alcohol is used as a cleaning fluid, as a solvent in many of aircraft finishes, and as a fuel for certain types of specialized engines.

Ethyl alcohol (the alcohol used in liquor) is distilled from fruit or grain, and methyl alcohol, which is poisonous, is distilled from wood pulp.