rad

/ræd/

/ræd/

Other forms: rads

Definitions of rad

1. noun

   a unit of absorbed ionizing radiation equal to 100 ergs per gram of irradiated material
   type of:

   radioactivity unit

   a measure of radioactivity
2. noun

   the unit of plane angle adopted under the Systeme International d'Unites; equal to the angle at the center of a circle subtended by an arc equal in length to the radius (approximately 57.295 degrees)
   synonyms: radian

   type of:

   angular unit

   a unit of measurement for angles