Word commonly used in the Vietnam war to describe a person whos eyes look asian, or slant. As in you could zip there face up. Also see gook which is another term to describe asians.

Used during vietnam, Charlie was coined zipperheads because of the way a head looked after it had been hit with a high powered automatic weapon. The the typical rising machine gun would cause a face wound that looked like an open zipper on the face of some one from the viet kong.