Late blow hampering current book show (7)
I believe the answer is:
exhibit
'show' is the definition.
(I know that show can be written as exhibit)
'late blow hampering current book' is the wordplay.
I cannot quite see how this works, but
'late' could be 'ex' (prefix meaning former or onetime) and 'ex' is present in the answer.
'current' could be 'i' (symbol for electric current) and 'i' is found in the answer.
'book' could be 'b' (abbreviation for book) and 'b' is found within the answer.
The remaining letters 'hit' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for exhibit that I've seen before include "Object on formal public display" , "Put on show" , "Something shown in public" , "Item in show" , "Demonstrate" .)