gunkday

The day (or several days) at the end of a common cold when your body is being "productive" and clearing out all the gunk and lungbutter. You may or may not be contagious, but folks will definitely steer clear.

Todd: Wow, Elliot should totally have stayed home for gunkday.
JD: Yeah, I always stay home for gunkday. That way I won't make my coworkers sick.
Perry: You make me sick.