Wedged beneath bank briefly, cuts slacks off (7)
I believe the answer is:
relaxes
'slacks off' is the definition.
The definition and answer can be both related to change as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?
'wedged beneath bank briefly cuts' is the wordplay.
'wedged beneath' becomes 'rels' (I am not sure about this - if you are sure you should believe this answer much more).
'bank' indicates putting letters inside (outside letters create limits or banks).
'briefly' means to remove the last letter.
'cuts' becomes 'axes' (both can mean to cancel or dismiss).
'axes' with its final letter taken off is 'axe'.
'rels' going around 'axe' is 'RELAXES'.
Can you help me to learn more?
(Other definitions for relaxes that I've seen before include "Moderates" , "Hangs loose" , "Slackens" , "Makes less tense" , "Takes it easy" .)