1) To have an extreme urge to defecate, so much so that the feces is already spreading the anus and a portion of it is beginning to stick out. So called because it resembles a turtle poking its head out of its shell.
2) The portion of a long log of shit that protrudes above the water in a toilet. Since it is above the water, it can be smelled. So called because it resembles a turtle poking its head out of the water.
1) May I use your bathroom? It's urgent, I have a turtle head poking out.
2) You may not want to go into the washroom for a while: I just had a crap and there was a turtle head poking out; the smell is awful.
This defines the feeling you get when an immediate and unmistakable urge to take a massive dump. It begins with a poking turtle, but you feel the ferocity of a hidden dragon behind it.
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.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).