a ratio between two portions of a line, or the two dimensions of a plane figure, in which the lesser of the two is to the greater as the greater is to the sum of both: a ratio of approximately 0.618 to 1.000.

the proportion of the two divisions of a straight line or the two dimensions of a plane figure such that the smaller is to the larger as the larger is to the sum of the two. If the sides of a rectangle are in this proportion and a square is constructed internally on the shorter side, the rectangle that remains will also have sides in the same proportionCompare golden ratio

The ratio between two numbers a and b chosen such that the ratio of a to b is equal to the ratio of a+b to a. Its value is approximately 1.618. Shapes with proportions equal to the golden section are observed especially in the fine arts and in architecture, as between the two dimensions of a plane figure such as a rectangle. The ratio between consecutive numbers in a Fibonacci sequence approximates the golden section with increasing precision as the series progresses. Also called golden meangolden ratio