To masturbate. Specifically refers to male masturbation. This usage gained popularity at universities in the midwest.
Hawk: Hey man whatcha doin?
Crab: Woah man close the door im doogin in here
Hawk: oh sorry man...need a hand?
Crab: No. get the fuck out, I can doog on my own faggot.
Hawk: chill dude, i thought we could have a doog off or something...