• Mathematical Association of Victoria of Victoria, Australia
• Micro air vehicle, a type of remotely controlled unmanned aerial vehicle
• Mojave Aerospace Ventures, the holding company for the SpaceShipOne space flight effort.
• Migraine Associated Vertigo, vertigo or dizziness resulting from migraine headache
• Multi Activity Vehicle, a category used by the auto industry

See also:

• MÁV (Hungarian abbreviation for Hungarian State Railways)
• Mavs, nickname for the Dallas Mavericks
• Mav, slang term used to refer to black people. From the Greek word mavro meaning black.
• MAV - a MU* (MUCK/MUD/MUSH) computer culture term for a MAVerick post/tell that goes to someone other than its intended recipient.