Race rings round him (4)
I believe the answer is:
otto
'him' is the definition.
'race rings round' is the wordplay.
'race' becomes 'tt'.
'rings' becomes 'oo' (two O's - O resembles a ring).
'round' is an insertion indicator.
'tt' going into 'oo' is 'OTTO'.
(Other definitions for otto that I've seen before include "Name of four German kings" , "-- Klemperer, conductor" , "Palindromic fragrance" , "Rose oil; man's name" , "Something oily" .)