What is ancceleration?

Answer 1

Probably an incorrect spelling of "acceleration", which refers to the rate of change of velocity - how fast a velocity changes.

Perhaps the above answer should read speed and not velocity, as velocity means a change of direction? i.e The car accelerated from 60 kl per hr to 70 kl per hour travelling due north, then changed direction to NNW. The change in direction is a vector.