rad

Short definition from Wiktionary

Adjective

1. 1
   Clipping of radical (“excellent”).

Noun

1. 1
   A non-SI unit of absorbed dose of radiation, equal to 0.01 gray, that is, 1 centigray.
2. 2
   Symbol for the radian, a unit of measure for angle.
3. 3
   Clipping of radiator.
4. 4
   Abbreviation of sight radius.
5. 5
   Clipping of radical: a political radical.
6. 6
   Initialism of role activity diagram.
7. 7
   Initialism of rapid application development.
8. 8
   Initialism of reactive attachment disorder.

Proper noun

1. 1
   Initialism of Radiation Assessment Detector, a scientific instrument of the Mars Science Laboratory onboard the Curiosity rover at Mars.

Symbol

1. 1
   radian, unit of measure for angle