Exacts payment for something on another's account (7)
I believe the answer is:
avenges
'exacts' is the definition.
Although both the answer and definition are verbs in their -s form, I cannot see how one could define the other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for avenges that I've seen before include "Gets back at" , "Makes reprisal" , "Takes satisifaction for a wrongdoing or injury" , "Retaliates for" , "Carries out retribution" .)