Duke in circle with old queen is a flatterer (8)
I believe the answer is:
wheedler
'flatterer' is the definition.
(thesaurus)
'duke in circle with old queen' is the wordplay.
'duke' becomes 'd' (abbreviation).
'in' indicates putting letters inside.
'circle' becomes 'wheel' (wheel can mean to circle or turn).
'with' says to put letters next to each other.
'old queen' becomes 'ER' (Elizabeth Regina, ie Queen Elizabeth).
'd' placed inside 'wheel' is 'wheedl'.
'wheedl'+'er'='WHEEDLER'
'is a' acts as a link.
(Another definition for wheedler that I've seen is " Cajoling coaxer".)