acceleration

noun4

1. •
   The act of accelerating, or the state of being accelerated; increase of motion or action; as opposed to retardation or deceleration.

   • A falling body moves toward the earth with an acceleration of velocity.
2. •
   The amount by which a speed or velocity increases (and so a scalar quantity or a vector quantity).

   • The boosters produce an acceleration of 20 metres per second per second.
3. •
   The change of velocity with respect to time (can include deceleration or changing direction).
4. •
   The advancement of students at a rate that places them ahead of where they would be in the regular school curriculum.