Pronunciation: (ak-sel"u-rā'shun), [key]
1. the act of accelerating; increase of speed or velocity.
2. a change in velocity.
3. Mech.the time rate of change of velocity with respect to magnitude or direction; the derivative of velocity with respect to time.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.