steradian


steradian
steradian [stə rā′dē ən]
n.
[ STE(REO)- + RADIAN]
the basic unit of solid angular measure in the SI system, equal to the solid angle subtended at the center of a sphere by an area, on its surface, that is equal to the square of its radius: one sphere equals 4π steradians: abbrev. sr

English World dictionary. . 2014.