Queen turned over in check (4)
I believe the answer is:
rein
'check' is the definition.
(both can mean to control or limit)
'queen turned over in' is the wordplay.
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'turned over' says the letters should be written in reverse.
'er' back-to-front is 're'.
're'+'in'='REIN'
(Other definitions for rein that I've seen before include "Free ... is carte blanche" , "given free to experienced riders?" , "Hold back" , "Horse controller" , "Controlling strap" .)