Wrecked ship man has study not completed (8)
I believe the answer is:
hesperus
'wrecked ship' is the definition.
The definition suggests a singular noun which matches the answer.
'man has study not completed' is the wordplay.
I cannot really understand how this works, but
'man' could be 'he' (he refers to a man) and 'he' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for hesperus that I've seen before include "Name for Venus" , "Evening star; Longfellow's Wreck" , "star in the evenings" , "Longfellow poem 'The Wreck of the ??..' (8)" .)