A peer may have one, high tea with Corbyn (9)
I believe the answer is:
baronetcy
'a peer may have one' is the definition.
(a baron is a type of peer)
'high tea with corbyn' is the wordplay.
'high' indicates anagramming the letters (can mean drunk or on drugs and hence disordered).
'with' means one lot of letters go next to another.
'tea' after 'corbyn' is 'corbyntea'.
'corbyntea' is an anagram of 'BARONETCY'.
(Other definitions for baronetcy that I've seen before include "Title" , "Lowest hereditary honour" .)