A person in whose mouth one puts one's cock to shut said person up. The opposite of a jukebox in which one deposits something in in order to hear something.
from Overheard In New York

You've Been Waiting for an Excuse to Use That One, Haven't You?

NYU girl: I'm not surprised that she has mono. I mean, she's been a slut for a while now. It was bound to catch up with her.
Friend: Yeah, she's a reverse jukebox.
NYU girl: A what?
Friend: You know how you put money into a jukebox and it makes noise? Guys put their dicks in her to make her shut the fuck up.

--NYU Silver Center
by O.I.N. June 7, 2009
Get the Reverse Jukebox mug.