General Purpose Vehicle - G.P.
The original vehicle which first appeared as the prototype Bantam BRC became the primary light 4-wheel-drive vehicle of the US Army and allies during the World War II and postwar period.
Many vehicles serving similar military and civilian roles have since been created by many nations.
Probably the most popular notion holds that the vehicle bore the designation "GP" ("General Purpose"), which was phonetically slurred into the word "Jeep".