State a greeting in circles (4)
I believe the answer is:
ohio
'state' is the definition.
(I know that Ohio is a state)
'a greeting in circles' is the wordplay.
'a greeting' becomes 'hi' (hi is a kind of greeting).
'in' means one lot of letters goes inside another.
'circles' becomes 'oo' (resembles two O's).
'hi' inserted within 'oo' is 'OHIO'.
(Other definitions for ohio that I've seen before include "The Buckeye State" , "American state, capital Columbus" , "E. central US state" , "part of the Midwest!" , "great river" .)