An alcohol is an organic compound that contains a hydroxyl group (–OH) bonded to a saturated, sp³-hybridised carbon. The hydroxyl group is the functional group; it makes alcohols polar and able to form hydrogen bonds, and it can be replaced or eliminated in many reactions. Alcohols are named with the suffix '-ol'; for example, ethanol. The requirement for a saturated carbon distinguishes an alcohol from a phenol, in which –OH is bonded to an aromatic ring.

醇是含有羟基(–OH)、且羟基连接在饱和的 sp³ 杂化碳上的有机化合物。羟基即为官能团;它使醇具有极性并能形成氢键,且在许多反应中可被取代或消除。醇以词尾“-ol(醇)”命名;例如乙醇。要求连在饱和碳上这一点使醇区别于酚,后者的 –OH 连在芳环上。