1.NounThe velocity of an object at any given instant (especially that of an accelerating object).
2.NounThe limit of the change in position per unit time as the unit of time approaches zero; expressed mathematically as
lim
t
→
0
Δ
x
Δ
t
{\displaystyle \lim _{t\to 0}{\frac {\Delta x}{\Delta t}}}