When taking drugs, this word is most commonly used in a sesh meaning someone is tripping out, or is just fucking out of it.
Josh: yoo Evan bro you good?
Evan: (lying in an inhuman position, possibly with his eyes in the back of his head) yea mate just bookin out lemme trip
Nathan: oi Josh he's good he'll be back in a min
Josh: bet, who wants another line?
Evan: (lying in an inhuman position, possibly with his eyes in the back of his head) yea mate just bookin out lemme trip
Nathan: oi Josh he's good he'll be back in a min
Josh: bet, who wants another line?
by Evan the addict x April 12, 2019