A word guys at my high school, Rockhurst high school class of 2003, created and would use at random in all sorts of circumstances.
It can mean anything and be used at any time. It can be used as an answer to a question or the question itself. It can be used to fill a silence or to interrupt someone. There really are no limits on "jevum".
The only constant is that people would laugh when "jevum" is uttered.