1. One who, or that which, gives a name; origin or source of a name. "This opinion that Aram . . . Was the father and denomination of the Syrians in general." (Sir W. Raleigh)

2. <mathematics> That number placed below the line in vulgar fractions which shows into how many parts the integer or unit is divided.

Thus, in 3/5, 5 is the denominator, showing that the integer is divided into five parts; and the numerator, 3, shows how many parts are taken.

3. <mathematics> That part of any expression under a fractional form which is situated below the horizontal line signifying division.

In this sense, the denominator is not necessarily a number, but may be any expression, either positive or negative, real or imaginary.

Origin: Cf. F. Denominateur.

(01 Mar 1998)