Mend a couple more before Mo leaves (6)
I believe the answer is:
repair
'mend' is the definition.
(synonyms)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for repair that I've seen before include "Restore after damage" , "Mend - go" , "Restore to working condition" , "Correct" , "do some darning" .)