When you become so dirty from outdoor activities (i.e. train hopping, camping, sleeping in a dirt lot) that no matter how hard you scrub you just can't get it off and you just have to wait it out. Also includes dirt that can not be removed from under your nails.
"I made Jack take a shower before I would have sex with him, he said he just took a shower, but it turned out he was hobo dirty."
by Anarchaprimitivist July 17, 2012