Disconcerted queen sits on this, they say (6)
I believe the answer is:
thrown
'disconcerted' is the definition.
(I've seen this before)
'queen sits on this they say' is the wordplay.
'queen sits on this' becomes 'throne'.
'they say' indicates a 'sounds like' (homophone) clue.
'throne' is a homophone of 'THROWN'.
(Other definitions for thrown that I've seen before include "Disconcerted, confused" , "Confused - cast" , "Unseated" , "Defeated" , "Disconcerted; chucked" .)