Sovereign relations good (4)
I believe the answer is:
king
'sovereign' is the definition.
(king is a kind of sovereign)
'relations good' is the wordplay.
'relations' becomes 'kin' (both can mean one's family).
'good' becomes 'g' (abbreviation).
'kin'+'g'='KING'
(Other definitions for king that I've seen before include "Senior royal" , "- Cobra; - crab; - post; - prawn" , "Male ruler" , "Sovereign" , "Chess piece" .)