chapossum Share definition Flag mix between chipmunk and possum; used to describe a girl who goes after hot guys even though she's über-ugly. Originated in 2007 in Onekama School in Onekama, MI. Girl: Oh, look at that stud!Guy Friend: Shut up, you little chapossum... There's no chance in hell. chapossum by nadlena June 5, 2009 0 0 Get merch Get the chapossum mug. Buy Now — $32.95 See more merch