celerity

Short definition from Wiktionary

Noun

1. 1
   Speed, swiftness.
2. 2
   The speed of an individual wave (as opposed to the speed of groups of waves); often denoted c.
3. 3
   The speed of an individual wave (as opposed to the speed of groups of waves); often denoted c: The speed with which a perturbation to the flow propagates through the flow domain.
4. 4
   The speed of symbol transmission, now called baud rate.