n. When dining in at Wendy's, it is the act of smearing a Frosty all over one's face.
This action can be done on one's own face or on another's face (the "target"). If the actor is attempting to frosty facial a "target", one effective line is: "This Frosty smells funny." When the dessert/beverage is close the target's nose, proceed to apply force on the cup towards the target's face.
Origin is unclear, although sociologists and psychiatrists suggest its first usage comes from high school track athletes from the state of Michigan.
Thompson just talked about your mom and did a Frosty facial.