A nickname of the township outside of Philadelphia called Upper Darby. It is called this because its full of scum, and roughly 2 of 3 girls are pregnant. Only about 5% of the Upper Dirty population take showers on a regular basis, and all these facts lead to the nickname.
by J. Wolff May 16, 2006
Steve couldn't imagine Matt kissing Kelly because her dirty upper lip would have tickled or made it seem as if he were kissing a man.
by pseudonym338 May 25, 2012