A female who receives oral sex, while she is defecating; the female version of a "blumpkin"
1) Frat Boy talking to other frat friends: "Dude...I blacked out last night and totally dopplered this girl I just met at the bar."
2) Slutty girl talking to other slutty friends: "So there I was on the crapper dropping this wicked dump, when in comes this retarded frat kid with a grin on his face asking if I want a doppler. He suddenly does a reverse handstand, drops his head between my thighs and goes to work. I finished dumping, of course....."