rapidity (n.)
- alacrity
- bat
- briskness
- ceaselessness
- celerity
- chattering
- constancy
- continuity
- decisiveness
- dispatch
- expedition
- expeditiousness
- fastness
- flight
- flit
- flurry
- gait
- haste
- hurry
- immediacy
- immediateness
- incessancy
- instantaneousness
- oscillation
- pace
- perpetuity
- precipitation
- promptitude
- promptness
- pulsation
- punctuality
- quickness
- readiness
- regularity
- repetition
- rpm
- rush
- speed
- speediness
- steadiness
- sustainment
- swiftness
- tattoo
- velocity
- vibration
