In 1937, the Army had created the vehicle for traveling purposes in difficult areas of the world. Four-wheel drive vehicles which could climb or move over hardcore areas. They named it G.P at that very moment there was a cartoon called Popeye it was a famous show, there was a new character in the show, he was called Eugene The Jeep. He was a weird little pet for Olive Oil, when other characters called it they called it “jeep”. The army men saw the character in the show and brought the two words together. The vehicle was only called jeep from then on.
The G.P at the start meant government purpose or General Purpose. They named it after the pet of Olive because it could solve impossible problems much like the G.P which could maneuver over difficult terrain.