The term MASS X VELOCITY can be summarized as the concept of MOMENTUM, which is an 8 letter word. MOMENTUM is a physical quantity that is equal to the product of an object's mass and velocity. It is a measure of the object's tendency to remain in motion or to change its direction. MOMENTUM is a vector quantity, meaning it has both magnitude and direction. MOMENTUM is an important concept in physics, and is used to describe the motion of objects in various situations.