A person with messy hair that they haven't brushed in 3+ weeks. (maybe they don't wash it either) it's so gross that birds lay eggs in it thinking it's a nest. kashkoosh guys often have a kashkoosh moustache or beard as well.
Person 1: Ew! That guy's hair looks awful.
Person 2: Right?! Must be a kashkoosh.
When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.