an extremely unattractive person
This term was derived from the one-to-ten rating system people commonly use to rate the attractiveness of a potential mate. It seems that there is a serious babe drought in Antarctica, where scientists spend an entire winter in close quarters with eachother. Hence the term.
I didn't make this up. Some guy who went to Antarctica wrote about it in a 1999 article which appeared in the Wall Street Journal, IIRC.