Webster's 1828 Dictionary
PROMPTNESS
n.Readiness; quickness of decision or action. The young man answered questions with great promptness. 1. Cheerful willingness; alacrity.
2. Activity; briskness; as the promptness of animal actions.
Webster's 1913 Dictionary
PROMPTNESS
PROMPTNESS Prompt "ness, n.
1. Promptitude; readiness; quickness of decision or action.
2. Cheerful willingness; alacrity.
Oxford Thesaurus
promptness
promptness noun he acted with commendable promptness: speed, swiftness, speediness, rapidity, promptitude, alacrity, dispatch, quickness, expeditiousness, expedition, immediacy, instantaneousness, readiness, willingness, eagerness; punctuality.