Summer's work is complete (5)
I believe the answer is:
total
'is complete' is the definition.
(synonyms)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for total that I've seen before include "Whole, complete" , "Aggregate amount" , "Damage beyond repair" , "Ruin" , "Complete; add up" .)