An Italian poet, rather slow (7)
I believe the answer is:
andante
'rather slow' is the definition.
(musical direction)
'an italian poet' is the wordplay.
'italian poet' becomes 'dante' (Dante Alighieri).
'an'+'dante'='ANDANTE'
(Other definitions for andante that I've seen before include "not quickly" , "Musical instruction" , "Moderately slow movement" , "not hurrying from bar to bar" , "deliberately played" .)