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Vellum
(Vel"lum) n. [OE. velim, F. vélin, fr. L. vitulinus of a calf, fr. vitulus a calf. See Veal.] A fine
kind of parchment, usually made from calfskin, and rendered clear and white, — used as for writing
upon, and for binding books.
Vellum cloth, a fine kind of cotton fabric, made very transparent, and used as a tracing cloth.
Vellumy
(Vel"lum*y) a. Resembling vellum.
Velocimeter
(Vel`o*cim"e*ter) n. [L. velox, -ocis, rapid + -meter.] An apparatus for measuring speed,
as of machinery or vessels, but especially of projectiles.
Velocipede
(Ve*loc"i*pede) n. [L. velox, - ocis, swift + pes, pedis, a foot. See Velocity, and Foot.]
A light road carriage propelled by the feet of the rider. Originally it was propelled by striking the tips of
the toes on the roadway, but commonly now by the action of the feet on a pedal or pedals connected
with the axle of one or more of the wheels, and causing their revolution. They are made in many forms,
with two, three, or four wheels. See Bicycle, and Tricycle.
Velocipedist
(Ve*loc"i*pe`dist) n. One who rides on a velocipede.
Velocity
(Ve*loc"i*ty) n.; pl. Velocities [L. velocitas, from velox, -ocis, swift, quick; perhaps akin to
vlare to fly (see Volatile): cf. F. vélocité.]
1. Quickness of motion; swiftness; speed; celerity; rapidity; as, the velocity of wind; the velocity of a planet
or comet in its orbit or course; the velocity of a cannon ball; the velocity of light.
In such phrases, velocity is more generally used than celerity. We apply celerity to animals; as, a horse
or an ostrich runs with celerity; but bodies moving in the air or in ethereal space move with greater or
less velocity, not celerity. This usage is arbitrary, and perhaps not universal.
2. (Mech.) Rate of motion; the relation of motion to time, measured by the number of units of space
passed over by a moving body or point in a unit of time, usually the number of feet passed over in a
second. See the Note under Speed.
Angular velocity. See under Angular. - - Initial velocity, the velocity of a moving body at starting; especially,
the velocity of a projectile as it leaves the mouth of a firearm from which it is discharged. — Relative
velocity, the velocity with which a body approaches or recedes from another body, whether both are
moving or only one. — Uniform velocity, velocity in which the same number of units of space are
described in each successive unit of time. — Variable velocity, velocity in which the space described
varies from instant, either increasing or decreasing; — in the former case called accelerated velocity, in
the latter, retarded velocity; the acceleration or retardation itself being also either uniform or variable.
— Virtual velocity. See under Virtual.
In variable velocity, the velocity, strictly, at any given instant, is the rate of motion at that instant, and
is expressed by the units of space, which, if the velocity at that instant were continued uniform during a
unit of time, would be described in the unit of time; thus, the velocity of a falling body at a given instant
is the number of feet which, if the motion which the body has at that instant were continued uniformly
for one second, it would pass through in the second. The scientific sense of velocity differs from the
popular sense in being applied to all rates of motion, however slow, while the latter implies more or less
rapidity or quickness of motion.
Syn. — Swiftness; celerity; rapidity; fleetness; speed.
Velours
(Ve*lours") n. [F. See Velure.] One of many textile fabrics having a pile like that of velvet.
Veltfare
(Velt"fare) n. [See Fieldfare.] (Zoöl.) The fieldfare. [Prov. Eng.]
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