A member of a Greek lettered organization that is no longer an undergraduate student, but is actively involved in the organization. This is usually done by joining a graduate or alumni chapter of the organization.
The grad is a unit of plane angle, equivalent to of a full circle, dividing a right angle in 100. It is also known as gon, grade, or gradian (not to be confused with grade of a slope, nor with gradient). One grad equals of a degree or of a radian.