Said goodbye to what was viewed as bad (4,3)

I believe the answer is:

seen off

I'm a little stuck... Click here to teach me more about this clue!

'said goodbye to what' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'viewed as bad' is the wordplay.
'viewed as' becomes 'seen' (to view is to see. I am not sure about the 'as' bit.).
'bad' becomes 'off' (eg meat that's gone off is bad).
'seen'+'off'='SEEN OFF'

'was' acts as a link.

Can you help me to learn more?

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app