Ron's in the chair (6)
I believe the answer is:
'chair' is the definition.
(I know that throne is a type of chair of state)
'ron's in the' is the wordplay.
'in' indicates putting letters inside.
'ron' going within 'the' is 'THRONE'.
(Other definitions for throne that I've seen before include "A king or queen sits on it" , "Royal chair" , "toilet" , "Hornet (anag) -- lavatory" , "Ceremonial seat" .)