Famous aristocrat accepts thanks (7)
I believe the answer is:
notable
'famous' is the definition.
(I know that famous can be written as notable)
'aristocrat accepts thanks' is the wordplay.
'aristocrat' becomes 'noble' (noble is a kind of aristocrat).
'accepts' indicates putting letters inside.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'noble' enclosing 'ta' is 'NOTABLE'.
(Other definitions for notable that I've seen before include "Worthy of record" , "Big noise" , "Celebrated" , "Significant or distinguished" , "VIP" .)