Is unable to love some poetry (5)
I believe the answer is:
canto
'some poetry' is the definition.
(I've seen this before)
'is unable to love' is the wordplay.
'is unable to' becomes 'can't' (can not).
'love' becomes 'o' (love means zero in tennis).
'cant'+'o'='CANTO'
(Other definitions for canto that I've seen before include "Musical part" , "Major division of a long poem" , "Highest part in a piece of choral music -- act on (anag)" , "Main division of long poem" , "Portion of poem" .)