Hot pooh that was generated by a large McDonald's feast.
I have to take a major McSteamer after downing the Value Meal. Love them McRibs!
by P. Quimby's old fat brother January 20, 2009
1 more definition
The act of shitting on a thin, used McDonald's napkin that is lying on the other persons face.
When Kristina saw the crinkled up napkin hanging out of the trash can, it reminded her of the hot McSteamer Thomas gave her last weekend.
by DirtySanchez123456 November 22, 2013