The word mob has its origins in the 17th century when it was formed from the latin mobile vulgus, meaning a vacillating crowd. It now has multiple meanings.

1. A mob is a crowd - see mob rule, and crowd psychology
2. A worldwide e-mail-driven experiments in organizing groups of people who suddenly materialize in public places, interact with others according to a loose script and then dissipate just as suddenly as they appeared. You have to know someone to get invited. There's no website to go to for information, no ads in local papers -- the mob forms from e-mails that are forwarded from person to person. The Mob Project is the brainchild of a man publicly known only as Bill, who says he works in the "culture industry". (See flash mob.)
3. The mob is a slang term for the Mafia and other organized crime.
4. In MUDs and later MMORPGs, the term mob or MOB is an abbreviation for mobile object, or simply mobile - an NPC (non-player characters) or monster. (See Mob (computer gaming).)

See also

• Smart mob
• MOB (all caps)