The term GUN MOTION is composed of two words, 'GUN' and 'MOTION'. The first word, 'GUN', refers to a weapon that fires bullets or other projectiles. The second word, 'MOTION', refers to the act of moving or changing position. When combined, the term GUN MOTION can refer to the RECOIL of a GUN, which is the backward movement of the GUN when it is fired. RECOIL is caused by the force of the bullet being expelled from the GUN, and is an important factor in the accuracy of shooting.