A sternutation, or a sneeze, is a semi-autonomous, convulsive expulsion of air from the nose and mouth. This air can reach speeds of 100-200 mph.
Twenty-something girl on Metro who COULD NOT STOP TALKING to her companion:
"So do you hold it in, or is that just the way you sneeze? So you've never been able to just let loose and go 'AH-CHOOOOOO!'? What, are you afraid your eyes are going to like fly out of your head or something if you did that? Not that I think that woud really happen. But you know when you have let out a real huge sneeze...."