is a specific kind of: pace, rate.

is a broader term that covers: fleetness | immediacy, immediateness, instancy, instantaneousness | despatch, dispatch, expedition, expeditiousness | promptitude, promptness.

derivation: agile, nimble, quick, spry | quick, warm | immediate, prompt, quick, straightaway | quick, speedy | rapid | rapid, speedy | fast, flying, quick.