A
popular misconception by the 21st century kids that "rad" is
short for "radical", whilst it can be, it is more
popular with ex-hippies from the original counterculture of the sixties to stand for "rock and drugs", ergo, rad. Though, it can still be used in context as, "that party was really rad," but therefore implying that there was rock and drugs at the party.
L: What ever happen to just plain
sex, drugs, n rock n roll?
B: I
don't really know why they left the 's' out, I guess you could say rads.
Rads.