Nonet I’m arranging, say (7)
I believe the answer is:
mention
'say' is the definition.
(mentioning is a kind of saying)
'nonet i'm arranging' is the wordplay.
'arranging' indicates an anagram.
'nonet'+'im'='nonetim'
'nonetim' is an anagram of 'MENTION'.
(Other definitions for mention that I've seen before include "Passing reference" , "Allude to" , "state" , "Cite; quote" , "Speak of - refer to" .)