1) An exhibitionist and self-important grandiose person who cheapens the human race simply by existing.
2) Someone who is incredibly vapid and has no concept of reality or offers any kind of discernible value to society.
3) A cunt.
So named because of the antics of contestants of the UK version of the "popular" Channel Four reality television programme of the same name.
1) Person One: I've just applied to go on Big Brother so I can spout my half baked political philosophies and act like a tit by having a temper tantrum or being racist the name of entertainment. Oh, and I have a wacky name like Gizmotech or DJ Baztarrd.
Person Two: Oh, for fuck's sake.
2) Person One: I want to earn a soft porn modelling contact, bag a footballer and attempt to live off my grossly distorted peception of my own beauty for the rest of my life.
Person Two: As oddly eloquent as that sentence was, I think your best bet is to become a Big Brother Contestant. Or kill yourself. Now.
3) Person One: I just pushed that old lady in front of that bus then pimp slapped the taste from out of that small child's mouth.
Person Two: You're such a Big Brother Contestant.