What is "gradian"

n. (label en geometry trigonometry) A unit of angle equal to 0.9 degrees, so that there are 100 gradians in a right angle.

The gradian is a unit of measurement of an angle, equivalent to of a turn, of a degree or of a radian.

It is also known as gon (from Greek /gōnía for angle), grad, or grade. In continental Europe, the French term centigrade was in use for one hundredth of a grad. This was one reason for the adoption of the term Celsius to replace centigrade as the name of the temperature scale.