coefficient

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A number or symbol multiplied with a variable or an unknown quantity in an algebraic term, as 4 in the term 4x, or x in the term x(a + b).
2. n. A numerical measure of a physical or chemical property that is constant for a system under specified conditions such as the coefficient of friction.

Century Dictionary and Cyclopedia

1. Coöperating; acting in union to the same end.
2. n. That which unites in action with something else to produce a given effect; that which unites its action with the action of another.
3. n. In algebra, a number or other constant placed before and multiplying an unknown quantity or variable or an expression containing such quantities; also, a number multiplying a constant or known quantity expressed algebraically—that is, by the letters a, b, etc. Thus, 3 is the coefficient of x, 2ab the coefficient of y, and 2 the coefficient of ab. in the polynomial 3x + 2aby.
4. n. In physical, a numerical quantity, constant for a given substance, and used to measure some one of its properties: as, the coefficient of expansion of any substance is the amount which the unit of length (surface or volume) expands in passing from 0° to 1° C.
5. n. Same as coefficient of variation.
6. n. Superior lethal coefficient, that medium concentration of a disinfectant which will kill bacteria spores in water at a temperature of 20–25° C. in the shortest time.
7. n. The coefficient of change in electrical resistance of a substance with variation of temperature. The temperature coefficient is given by the equation: in which r is the resistance of the substance at the temperature t_o, and r_o, its resistance at 0°.

Wiktionary

1. adj. cooperating
2. n. mathematics A constant by which an algebraic term is multiplied.
3. n. A number, value or item that serves as a measure of some property or characteristic.

GNU Webster's 1913

1. adj. Coöperating; acting together to produce an effect.
2. n. That which unites in action with something else to produce the same effect.
3. n. (Math.) A number or letter put before a letter or quantity, known or unknown, to show how many times the latter is to be taken.
4. n. (Physics) A number, commonly used in computation as a factor, expressing the amount of some change or effect under certain fixed conditions as to temperature, length, volume, etc..

WordNet 3.0

1. n. a constant number that serves as a measure of some property or characteristic