'Rapidity' definitions:

Definition of 'rapidity'

From: WordNet
noun
A rate that is rapid [syn: celerity, quickness, rapidity, rapidness, speediness]

Definition of 'Rapidity'

From: GCIDE
  • Rapidity \Ra*pid"i*ty\ (r[.a]*p[i^]d"[i^]*t[y^]), n. [L. rapiditas: cf. F. rapidit['e].] 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]