RAD

noun

1. A non-SI unit of absorbed dose of radiation, equal to 0.01 gray.

noun

1. In the International System of Units, the derived unit of plane angular measure of angle equal to the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle. Symbol: rad

noun

1. Anything which radiates or emits rays.
2. A device that lowers engine coolant temperature by conducting heat to the air, through metal fins.
3. (of buildings) A finned metal fixture that carries hot water or steam in order to heat a room.