A large disorderly crowd or throng. See Synonyms at crowd1. The mass of common people; the populace. Informal An organized gang of criminals; a crime syndicate. Informal Organized crime. Often used with the: a murder suspect with links to the Mob. An indiscriminate or loosely associated group of persons or things: a mob of boats in the harbor. Australian A flock or herd of animals. To crowd around and jostle or annoy, especially in anger or excessive enthusiasm: Eager fans mobbed the popular singer. To crowd into: Visitors mobbed the fairgrounds. To attack in large numbers; overwhelm: The quarterback was mobbed by the defensive line.