When you are dabbed out, you are so high due to taking dabs (Butane Hash Oil) that you are in a state of (semi/
un)consciousness.
It this level of high, the
user is unable to take another
dab, thus "dabbed out".
Tony: "Oh man it's so late but I haven't even caught a buzz yet... Are you tryin' to do another dab?"
Blake: *zzz*
Tony: "
BLAKE! Wake the hell up man..."
Blake: "Wha-... Oh shit. Sorry man I've been smoking all day, I'm dabbed out."