This is a comeback/remark acronym that means "none of your business". It can be modified and
intensified by adding letters like "NOYDB" or "NOYFB" for "none of your damn business" or "none of your fucking business". These are used when you want to make it clear to someone that they have overstepped a line/boundary and
you are not comfortable sharing particular information with them.
Person 1: When are
you going to
the party?
Person 2: NOYB.
Person 1: ok, sheesh, sorry I asked...
Person A: What's your address so I can see how far you live from me?
Person B: NOYFB!!!
Person A: K...
Person A1: How much money do you make an hour?
Person B2: NOYDB......
Person A1: It is though, I help you with
your taxes...
Person B2: Idfc