Define velocity. Define average velocity.

(N/A) Velocity: The rate of change of displacement of an object with respect to time is called velocity. It is a vector quantity,meaning it has both magnitude and direction. The $SI$ unit of velocity is $m/s$.
Average velocity: The average velocity of an object is defined as the total displacement divided by the total time interval taken to cover that displacement. Mathematically,$v_{avg} = \frac{\Delta x}{\Delta t}$,where $\Delta x$ is the total displacement and $\Delta t$ is the total time interval.