Top definition
the product of putting milk and ice cream in ones butthole and pooping it out. The buttmilk shake is commonly served in a tall glass with a long sppon and a straw.
"Erin Jane put half a pint of Breyer's french vanilla up her butt and made a delicious buttmilkshake for her enjoyment"
by tortillachipgrl69 April 15, 2009
Get the mug
Get a buttmilkshake mug for your guy Yasemin.