Wanted something done about gentleman (7)
I believe the answer is:
desired
'wanted' is the definition.
('desired' can be similar in meaning to 'wanted')
'something done about gentleman' is the wordplay.
'something done' becomes 'deed' (I've seen this before).
'about' is an insertion indicator.
'gentleman' becomes 'sir' (I've seen this before).
'deed' placed around 'sir' is 'DESIRED'.
(Other definitions for desired that I've seen before include "requested" , "Lusted-after" , "Wanted strongly" , "Wanted greatly" , "much wished for" .)