5. (Science: mathematics) A single thing, as a magnitude or number, regarded as an undivided whole. Abstract unit, the unit of numeration; one taken in the abstract; the number represented by 1. The term is used in distinction from concrete, or determinate, unit, that is, a unit in which the kind of thing is expressed; a unit of measure or value; as 1 foot, 1 dollar, 1 pound, and the like.
Complex unit, an imaginary number of the form a _ b-1, when a^2 _ b^2 = 1. Duodecimal unit, a unit in the scale of numbers increasing or decreasing by twelves. Fractional unit, the unit of a fraction; the reciprocal of the denominator; thus, 1/4 is the unit of the fraction 3/4. Integral unit, the unit of integral numbers, or 1. Physical unit, a value or magnitude conventionally adopted as a unit or standard in physical measurements. The various physical units are usually based on given units of length, mass, and time, and on the density or other properties of some substance, for example, water. See Dyne, Erg, Farad, Ohm, Poundal, etc.
(Science: biology) Unit deme, stress per unit of area; intensity of stress. It is expressed in ounces, pounds, tons, etc, per square inch, square foot, or square yard, etc, or in atmospheres, or inches of mercury or water, or the like.
Origin: Abbrev. From unity.