It is commonly used after a really bad or cheesy joke accompanied with a really bizarre hand gesture (sometimes shaking the person while holding his/her shoulders, recurrently blurting "biff").
It is also used as a logical connector between topics during conversations.
Some uses the word to break awkward silence between conversations, or, if the person has nothing else to say.
Some brave adventurers uses the expression in exams or in class during a short moment of silence.
Can be also used to greet people.
Has many variants such as "miff" and "brrrrrrrrrrrrrrrr" (although "brrrrrr" was the original expression that soon evolved into "biff").
The origins of this word is unknown but unverified sources suggest that it was imported from the Polaks.
"Doctor, doctor, I can't feel my legs!" The doctor replied "I know you
can't, I've cut your arms off".