The Collaborative International Dictionary of English v.0.48:
Quantity \Quan"ti*ty\, n.; pl. Quantities. [F. quantite, L.
quantitas, fr. quantus bow great, how much, akin to quam bow,
E. how, who. See Who.]
1. The attribute of being so much, and not more or less; the
property of being measurable, or capable of increase and
decrease, multiplication and division; greatness; and more
concretely, that which answers the question "How much?";
measure in regard to bulk or amount; determinate or
comparative dimensions; measure; amount; bulk; extent;
size. Hence, in specific uses:
(a) (Logic) The extent or extension of a general
conception, that is, the number of species or
individuals to which it may be applied; also, its
content or comprehension, that is, the number of its
constituent qualities, attributes, or relations.
(b) (Gram.) The measure of a syllable; that which
determines the time in which it is pronounced; as, the
long or short quantity of a vowel or syllable.
(c) (Mus.) The relative duration of a tone.
2. That which can be increased, diminished, or measured;
especially (Math.), anything to which mathematical
processes are applicable.
Note: Quantity is discrete when it is applied to separate
objects, as in number; continuous, when the parts are
connected, either in succession, as in time, motion,
etc., or in extension, as by the dimensions of space,
viz., length, breadth, and thickness.
3. A determinate or estimated amount; a sum or bulk; a
certain portion or part; sometimes, a considerable amount;
a large portion, bulk, or sum; as, a medicine taken in
quantities, that is, in large quantities.
The quantity of extensive and curious information
which he had picked up during many months of
desultory, but not unprofitable, study. --Macaulay.
Quantity of estate (Law), its time of continuance, or
degree of interest, as in fee, for life, or for years.
--Wharton (Law Dict. )
Quantity of matter, in a body, its mass, as determined by
its weight, or by its momentum under a given velocity.
Quantity of motion (Mech.), in a body, the relative amount
of its motion, as measured by its momentum, varying as the
product of mass and velocity.
Known quantities (Math.), quantities whose values are
Unknown quantities (Math.), quantities whose values are