GNU Collaborative International Dictionary of English

Found 2 definitions

1.       
   Rad , n. [radiation absorbed dose.] A unit of measurement of the amount of ionizing radiation absorbed by an object, equal to an energy of 100 ergs per gram of irradiated material (equal to 0.01 gray).
   PJC
         
       

2.       
   Rad , obs. imp. & p. p. of Read, Rede.
   Spenser.
   
   1913 Webster