When you want to call a friend a stupid dumbass, but while saying it you realize he/she is physically dangerous, so you stop short while saying dumbass.
Stupid Dumb Bitches are those who go above and beyond the steryotypical actions of both stupid bitches, as well as dumb bitches. SDB's can be utilized in any manner and treated with little respect.
Devan is a stupid dumb bitch.
Go get me a sammich, you stupid dumb bitch.
I heard that girl amanda j. has herpes and doesnt wash her self... what a SDB.