According to folk-comedy duo Flight of the Conchords, Mutha'uckas are people who " 'uck with your shi-", such as a racist fruit vendor, or people who work at the bank.
it can also be a thing, such as "mutha uckin rent"
1) I pay my mutha'uckin' rent fortnightly
Mutha'uckas at the bank trying to play me
2) The mutha'ucka runs a racist 'uckin' grocery
The mutha'ucka won't sell an apple to a Kiwi
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).