Very mean, that’s clear (9)
I believe the answer is:
vindicate
'clear' is the definition.
(I've seen this before)
'very mean' is the wordplay.
'very' becomes 'v' (abbreviation).
'mean' becomes 'indicate'.
'v'+'indicate'='VINDICATE'
'that's' is the link.
(Other definitions for vindicate that I've seen before include "support" , "Successfully defend" , "Deflect criticism" , "Justify by evidence or results" , "Clear of blame" .)