Source : Webster's Revised Unabridged Dictionary (1913)

Promptness \Prompt"ness\, n.
   1. Promptitude; readiness; quickness of decision or action.

   2. Cheerful willingness; alacrity.

Source : WordNet®

promptness
     n 1: the characteristic of doing things without delay [syn: {promptitude}]
     2: the quality or habit of adhering to an appointed time [syn:
        {punctuality}] [ant: {tardiness}]