Airmen in court, sergeant-major and an artificer (9)
I believe the answer is:
craftsman
'artificer' is the definition.
(I know that artificer can be written as craftsman)
'airmen in court sergeant-major and an' is the wordplay.
'airmen' becomes 'RAF' (Royal Air Force).
'in' means one lot of letters goes inside another.
'court' becomes 'ct' (abbreviation used in road names).
'sergeant major' becomes 'SM' (abbreviation for sergeant major).
'and' says to put letters next to each other.
'raf' inserted within 'ct' is 'craft'.
'craft'+'sm'+'an'='CRAFTSMAN'
(Other definitions for craftsman that I've seen before include "Carpenter, say" , "Skilled worker" , "Expert" , "Artisan" .)