look up any word, like steppin on my dick:
Throwing up an "M" using the same fingers allocated for "Westside". Derived from Alex Miller of CSUF Hockey and is the coolest thing you can do.
My teacher gave me an A on my test so I threw up a Mill-Sauce in the middle of class.

Throw up a Mill-Sauce after a poke-check.

Mill-Sauce while you are helicoptering,piloting, or auto-pilot while throwing up a double Mill-Sauce.
by Mill-Sauce August 25, 2010