greatest common denominator

Webster's Dictionary (GCIDE)

1.One who, or that which, gives a name; origin or source of a name. [1913 Webster]

This opinion that Aram . . . was the father and denomination of the Syrians in general.— Sir W. Raleigh.[1913 Webster]

2.(Arith.) That number placed below the line in common fractions which shows into how many parts the integer or unit is divided. [1913 Webster]

Note: 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. [1913 Webster]

3.(Alg.) That part of any expression under a fractional form which is situated below the horizontal line signifying division. [1913 Webster]

Note: In this sense, the denominator is not necessarily a number, but may be any expression, either positive or negative, real or imaginary. --Davies & Peck (Math. Dict.) [1913 Webster]

common denominator a number which can divide either of two or more other numbers without leaving a remainder in any of the divisions; as, 2 and 4 are common denominators of 12 and 28..

greatest common denominator the largest common denominator of two or more numbers; as, 9 is the greatest common denominator of 18 and 27.. [PJC]