Exclusive circle (7)
'exclusive circle' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for coterie that I've seen before include "Exclusive circle of people, clique" , "Small exclusive group of people" , "Group, band" , "Select group" , "Exclusive circle of people with common purpose" .)
(Another definition for ingroup that I've seen is " Like-minded people".)