FBW... A Senior Lazy Bastard is a member of staff who worked their 'nuts' off for at least the first three years they were employed by the company, thereby gaining a reputation for being a conscientious, reliable and valued member of the team.
Consequently, after this unofficial qualifying period, any lateness; arrogance; arguments with management; punching first officers; shouting at passengers; pranging airliners, etc. that may occur is just put down to 'having a bad day'. It is a licence to be a **** to anyone you like, also being safe in the knowledge that your D.O.J means that redundancy would cost the paymasters a fortune. Sorry to be so cynical, but you did ask!