Unbeliever witnessing bank job? (7)
I believe the answer is:
atheist
'unbeliever' is the definition.
(atheist is a kind of unbeliever)
'witnessing bank job?' is the wordplay.
'witnessing' becomes 'at' (I can't explain this - if you can you should give a lot more credence to this answer).
'bank job?' becomes 'heist' (I've seen this in another clue).
'at'+'heist'='ATHEIST'
Can you help me to learn more?
(Other definitions for atheist that I've seen before include "One denies the existence of a god" , "Person who does not believe in existence of a god" , "Person who believes there is no God" , "I don't believe" , "One denies the existence of gods" .)