Also 6 Sc. velocite, 6–7 velocitie. [ad. F. vélocité (14th cent.; = It. velocità, Sp. velocidad, Pg. -idade) or L. vēlōcitāt-, vēlōcitās, f. vēlōci-, vēlox swift, rapid: see -ITY.]
1. Rapidity or celerity of motion; swiftness, speed.
c. 1550. Rolland, Crt. Venus, II. 672. Thay bad him pas with all velocite To the Gracis.
1555. Eden, Decades (Arb.), 220. This byrde … is of such velocitie and swyftnes in flying that [etc.].
1607. Topsell, Four-f. Beasts, 115. The Lybian Roes … (saith hee) are of an admirable velocity or swiftnes.
1646. Sir T. Browne, Pseud. Ep., 235. Dolphins … Being the Hyeroglyphick of celerity,… men best expressed their velocity by incurvity, and under some figure of a bowe.
1665. Glanvill, Scepsis Sci., xi. 61. The supposed motion will be near a thousand miles an hour under the Equinoctional line; yet it will seem to have no Velocity to the sense.
1704. Fuller, Med. Gymn. (1711), 14. His Blood flows with its due Velocity.
1789. Mrs. Piozzi, Journ. France, II. 370. Black heaths, and wild uncultivated plains, over which the unresisted wind sweeps with a velocity I never yet was witness to.
1802. Bingley, Anim. Biog. (1805), III. 74. Some of the species … are enabled to spring with great force and velocity on their prey.
1849. Macaulay, Hist. Eng., iii. I. 379. The flying coaches are extolled as far superior to any similar vehicles ever known in the world. Their velocity is the subject of special commendation.
b. spec. Relative rapidity; rate of motion.
1656. trans. Hobbes’ Elem. Philos. (1839), 113. Motion, in as much as a certain length may in a certain time be transmitted by it, is called Velocity or swiftness: &c.
1715. trans. Gregory’s Astron. (1726), I. 91. The Velocity in A is to the Velocity in P, as SN to SH. But as the Velocities in A and P, so are the Spaces run in the same time, by the Bodies.
1743. W. Emerson, Fluxions, v. It is the general Practice in Mechanics, to measure the Velocity of a Body by the Space uniformly described in a given Time.
c. 1790. Imison, Sch. Arts, I. 1. Mechanics is a science which treats of the forces, motions, velocities, and in general, of the actions of bodies upon one another.
1813. Bakewell, Introd. Geol., Pref. (1815), 16. In mechanics, the important question of the ratio between the velocity and momentum is still undecided.
1857. Livingstone, Trav., xvi. 284, note. A declivity of three inches per mile gives a velocity in a smooth straight channel of three miles an hour.
1880. Haughton, Phys. Geogr., iii. 137. It has … a velocity of upwards of three knots per hour.
2. Rapidity (absolute or relative) of operation or action; quickness.
a. 1674. Clarendon, Surv. Leviath. (1676), 18. Mr. Hobbes … was with the velocity of a thought … able to decipher that impertinent Question.
1743. W. Emerson, Fluxions, 2. He will find some to increase faster, others slower; and consequently that there are comparative Velocities (or Fluxions) of Increase during their Generation.
1794. Hutton, Philos. Light, etc., 198. Neither the quantity of the fire, nor the velocity of its propagation.
1817. Jas. Mill, Brit. India, II. V. v. 479. Colonel Brathwaite was instructed to anticipate resistance by velocity of completion.
1858. Froude, Hist. Eng., IV. 481. The velocity with which the English world was swept into the New Era.
1871. B. Stewart, Heat (ed. 2), 228. The rate at which it loses temperature or the velocity of cooling.
3. attrib. and Comb., as velocity-measurer, potential, ratio.
1849–50. Weale, Dict. Terms, s.v. Velocimeter, Such a velocity-measurer was constructed by Breguet, of Paris.
1878. W. K. Clifford, Dynamic, III. 203. The circulation along any path from o to p … is called the velocity-potential at p.
1882. Minchin, Unipl. Kinemat., 160. If … the velocity potential has at each point of the curve an assigned value.
1887. D. A. Low, Machine Draw. (1892), 36. Velocity Ratio in Belt Gearing.
