n. [ L. rapiditas: cf. F. rapidité. ] The quality or state of being rapid; swiftness; celerity; velocity; as, the rapidity of a current; rapidity of speech; rapidity of growth or improvement. [ 1913 Webster ]
Syn. -- Rapidness; haste; speed; celerity; velocity; swiftness; fleetness; quickness; agility. [ 1913 Webster ]