The hydroxyl group (-OH) is an important functional group in organic chemistry. Synonyms for hydroxyl group include hydroxy, hydroxyl radical, hydroxide ion, and alcohols. While hydroxy and hydroxyl are the most commonly used synonyms for the group, hydroxyl radical refers to a molecule that contains an unpaired electron and is highly reactive, while hydroxide ion refers to the negatively charged form of the group found in aqueous solutions. Alcohols are a broader group of organic compounds that contain one or more hydroxyl groups attached to an alkyl or aryl group. Understanding the terminology and significance of hydroxyl groups is crucial for studying chemical reactions.