Give the lie to smear (9)

I believe the answer is:

discredit

I believe this clue is a double definition.

'give the lie to' is the first definition.
(I've seen this before)

'smear' is the second definition.
(I've seen this before)

(Other definitions for discredit that I've seen before include "Rubbish" , "To tarnish" , "damage to good name" , "Refuse to believe" , "Cast doubt" .)

I've seen this clue in The Sun and The Times.

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