"Pernicity" is a word in ENGLISH

Rapidity of motion; quickness; swiftness.

Swiftness; rapidity; velocity; celerity; speed; as, the fleetness of a horse or of time.

Celerity of motion; speed; swiftness; dispatch; expedition; -- applied only to voluntary beings, as men and other animals.

kadásig - Speed, rapidity, swiftness, velocity, quickness, celerity. (cf. dásig).

kalígsi - Swiftness, speediness, celerity, rapidity, fleetness, nimbleness, agility, quickness of movement. (lígsi; cf. kalíksi).

Light and quick in motion; moving with ease and celerity; lively; swift.

Very swift or quick; moving with celerity; fast; as, a rapid stream; a rapid flight; a rapid motion.

The quality or state of being rapid; swiftness; celerity; velocity; as, the rapidity of a current; rapidity of speech; rapidity …

Moving a great distance in a short time; moving with celerity or velocity; fleet; rapid; quick; speedy; prompt.

The quality or state of being swift; speed; quickness; celerity; velocity; rapidity; as, the swiftness of a bird; the swiftness …

túlin - Swiftness, celerity, velocity, fleetness, a steady straight course (of boats, birds, or the like); to cleave a path …

Quickness of motion; swiftness; speed; celerity; rapidity; as, the velocity of wind; the velocity of a planet or comet in …