Quote from Chandler in The One with Phoebe's Ex-Partner
Ginger: What's that? Chandler: That's my "nubbin." Ginger: What's a nubbin? Chandler: It's kind of a third-nipple kind of thing. Ginger: You have three nipples? Chandler: Well, you know, two regulars and one that barely qualifies as a- What? Ginger: Nothing. You know, l- I just remembered I have to leave. Chandler: You have to leave? Now? How come? Ginger: Well, it's nubbin. Nothing!