Distinguished aristocrat interrupted by cheers (7)
I believe the answer is:
notable
'distinguished' is the definition.
(I've seen this before)
'aristocrat interrupted by cheers' is the wordplay.
'aristocrat' becomes 'noble' (noble is a kind of aristocrat).
'interrupted by' is an insertion indicator.
'cheers' becomes 'ta' (both can informally mean thank you).
'noble' enclosing 'ta' is 'NOTABLE'.
(Other definitions for notable that I've seen before include "Eminent" , "celebrity" , "VIP" , "Unusual" , "Prominent" .)