middle-click 

to discretely alert a co-worker of an error they may be responsible for.

If Mike middle-clicks me one more time, I'm gonna staple his ass to his face.

middle-click by Michael Krumboltz October 3, 2003

Middle Chick 

Middle chick is a girl your talking to that your not sure about. Sure you'd like to have sex with her but your not 100% sure about it for various reasons including how much you actually like her, how crazy she is, etc.

I been talking to Jane but ehh shes a middle chick so who knows whats going happen, shes got lots of potential.

or

John keeps wasting time on that middle chick.

Middle Chick by chappygopappy March 22, 2010