rad 1
/rad/ , n. Physics.
a unit of absorbed dose equal to 0.01 Gy. Cf. dose (def. 4a).
[ 1915-20; shortened form of RADIATION ]
rad 2
/rad/ , n.
1. Informal. radical.
adj.
2. Slang. fine; wonderful.
[ by shortening of RADICAL ]
Math.
radian; radians.