1) A Welsh whore who could do things with her one good arm that'd make you forget that thing on her neck.
2) A certain fork in the Missouri river named after the said whore.
3) A derogatory slang term used to describe a sexually overactive and altogether unattractive female.
This term was popularized by Chris Farley while portraying the fictional character Bartholomew Hunt in 1998's Almost Heroes.
That sick old town bike was a real Pittsburgh Nelly.