Stop note being sent to peer (7)
I believe the answer is:
baronet
'to peer' is the definition.
(I've seen this before)
'stop note being sent' is the wordplay.
'stop' becomes 'bar' (bar can mean to stop or prevent).
'being sent' is an anagram indicator (send can mean to excite or stimulate).
'note' is an anagram of 'onet'.
'bar'+'onet'='BARONET'
(Other definitions for baronet that I've seen before include "Titled man" , "Lowest British hereditary title" , "Aristocrat" , "Nobleman" , "Member of the British order of honour" .)