A metaphor is a figurative language device that represents one thing as if it were another, or compares two things not normally viewed as similar, such as time is a thief. This comparison draws attention to the way time is quick and stealthy. Simile
Velocity is the rate of motion, speed or action. An example of velocity is a car driving at 75 miles per hour. velocity. pl. velocity. pl. Rapidity or speed of motion; swiftness. Physics A vector quantity whose magnitude is a body's speed and whose direction is the body's direction of motion.
Average velocity is the displacement (change in position) divided by time. Although speed and velocity are often words used interchangeably, in physics, they are distinct concepts. Speed is calculated by dividing the distance traveled by time. It does not have direction. Average velocity is the displacement (change in position) divided by time.