Become less severe about act that's evocative (8)
I believe the answer is:
redolent
'evocative' is the definition.
('redolent' can be a synonym of 'evocative')
'become less severe about act' is the wordplay.
'become less severe' becomes 'relent' (I've seen this before).
'about' indicates putting letters inside.
'act' becomes 'do' (I've seen this in other clues).
'relent' going around 'do' is 'REDOLENT'.
'that's' is the link.
(Other definitions for redolent that I've seen before include "Strongly suggesting" , "Smelling of, evocative" , "Fragrant; suggestive (of)" , "Aromatic" , "odorous" .)