Ra‐pid″i‐ty (rȧ‐pĭd″ĭ‐ty̆), 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.
Syn. — Rapidness; haste; speed; celerity; velocity; swiftness; fleetness; quickness; agility.