A variation of slut, used more as a derogative term pertaining to their intelligence rather than their promiscuity (however they are quite easy to get in bed). Derived from the mispronunciation of the phrase "Some dumb bitch": pronounce the o's as a's. Must be said in very dejected tone.
"Eh, pretty stupid. There was a gaggle of som doms blanketing the bar, so I couldn't even get a drink."