Group around a throne, perhaps (4)
I believe the answer is:
seat
'throne perhaps' is the definition.
(throne is a kind of seat)
'group around a' is the wordplay.
'group' becomes 'set' (both can mean a collection).
'around' means one lot of letters goes inside another.
'set' enclosing 'a' is 'SEAT'.
(Other definitions for seat that I've seen before include "'A chair, say (4)'" , "MP's place in parliament" , "Sitting place" , "Chair, bench, or stool, say" , "Constituency; location" .)