Check condition and restore (9)
I believe the answer is:
reinstate
'restore' is the definition.
(I know that restore can be written as reinstate)
'check condition' is the wordplay.
'check' becomes 'rein' (both can mean to control or limit).
'condition' becomes 'state' (the state something is in).
'rein'+'state'='REINSTATE'
'and' acts as a link.
(Other definitions for reinstate that I've seen before include "Restore to a former condition" , "Restore to a former position" , "Restore to previous state or rank" , "Put back in position" , "Restore to former post" .)