Nobleman who, in France, admitted to damages (7)
I believe the answer is:
marquis
'nobleman' is the definition.
(type of nobleman)
'who in france admitted to damages' is the wordplay.
'who in france' becomes 'qui' (French for 'who').
'admitted to' is an insertion indicator.
'damages' becomes 'mars' (marring is a kind of damaging).
'qui' placed within 'mars' is 'MARQUIS'.
(Other definitions for marquis that I've seen before include "Noble, above count" , "European nobleman" , "De Sade's title" , "Nob" , "Continental aristocrat" .)