What Cockney repairman does? Makes alterations! (6)
I believe the answer is:
emends
'makes alterations' is the definition.
Although both the answer and definition are verbs in their -s form, I can't understand how they can define each other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for emends that I've seen before include "'Corrects, puts right (6)'" , "Alters written material to remove errors" , "Makes improvements or corrections" , "Send me (anag.); corrects" , "Corrects and improves the text" .)