Man returns a book of poetry (6)
I believe the answer is:
stanza
'book of poetry' is the definition.
'stanza' can be an answer for 'book' (thesaurus). I am not certain of the 'of poetry' bit.
'man returns a' is the wordplay.
I cannot quite understand how this works, but
'man' could be 'stan' and 'stan' is found within the answer.
'a' is found in the answer.
A single letter 'z' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stanza that I've seen before include "Component of poem" , "Poetic unit" , "Fixed number of lines of verse" , "Chunk of poetry" , "piece of poetry" .)