Sundry poetry I would return first (7)
I believe the answer is:
diverse
'sundry' is the definition.
(I've seen this before)
'poetry i would return first' is the wordplay.
'poetry' becomes 'verse' (lines written in verse).
'i would' becomes 'I'd'.
'return' says the letters should be written in reverse.
'first' means one lot of letters go next to another.
'id' backwards is 'di'.
'verse' put after 'di' is 'DIVERSE'.
(Other definitions for diverse that I've seen before include "Miscellaneous" , "Disparate" , "Many and varied" , "Sundry" , "Of different kind or variety" .)