Ewa is like a greeting.
But ewaja is different it's hard to explain but when a friend did something cool you just say "ewaja" or when a friend is saying something that you agree with you say "ewaja".
You: "Ewa, how are you?"
Friend: "I'm great man, how are you?"
Friend:" I hate the English teacher, she's so dumb."
You:" Ewaja, same."
Friend:" I just skipped my exam but idc."
You:"Ewaja."
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).