Lobbying, practice of attempting to influence legislation. Lobbying is performed by agents, called lobbyists, of a particular interested group, known as the lobby. The lobbyist may request votes either for or against pending legislation. The term derives from the way in which these agents formerly confronted legislators in the lobby or hallways directly outside a legislative chamber. Lobbyists may represent such varied interests as agriculture, transport, professions such as medicine and the law, or such groups as women voters or conservationists.