There are a number of medical terms that I notice are routinely misused by the public. Not a week goes by, for example, that I don't hear a story about projectile vomiting. I can't remember the last time someone described their throw up as the regular brand. But upon questioning, none of the cases presented to me involved true projectile vomiting.
Vomiting is the forcible expulsion of stomach contents.
Projectile vomiting lacks preceding nausea and is sudden and so vigorous that the vomitus is forcefully projected to a distance. The puke arcs across the room and hits the wall. A baby who projectile vomits in bed will clear the end of the crib. The phenomenon is rare, and is typically associated with serious pathology, such as hypertrophic pyloric stenosis or increased intracranial pressure.
The emesis caused by bad Chinese food, a hangover or the flu, impressive though it may be, is just plain vomiting. Please don't try to dress it up.