A Lewis base is a chemical substance that donates an electron pair to a Lewis acid during a chemical reaction. Some common synonyms for a Lewis base include donor molecule, electron donor, or nucleophile. A nucleophile is another term used to describe a molecule that donates a pair of electrons to a chemical reaction. Basic compounds like ammonia, water, and alkoxides also act as Lewis bases. These compounds readily interact with and donate electrons to Lewis acids. Understanding the various synonyms for a Lewis base can help scientists and chemists better communicate and describe the properties and functions of these important chemical compounds in various reactions.