Simply cannot love this part of poem (5)
I believe the answer is:
canto
'this part of poem' is the definition.
('canto' is part of 'poem')
'simply cannot love' is the wordplay.
I cannot quite see how this works, but
'cannot' could be 'cant' (contraction) and 'cant' is present in the answer.
'love' could be 'o' (love means zero in tennis) and 'o' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for canto that I've seen before include "Section of a long poem" , "Each of sections into which long poem is divided" , "Main division of long poem" , "part of long poem" , "Poetic piece" .)