Bend or seizure grips back (7)
I believe the answer is:
endorse
'back' is the definition.
(back can mean to support or endorse)
'bend or seizure grips' is the wordplay.
'grips' indicates a hidden word (I've seen 'gripping' mean this (the answer is held or gripped within the clue)).
'ENDORSE' is hidden within 'bend or seizure'.
(Other definitions for endorse that I've seen before include "Uphold" , "Approve - support" , "Approve of, sign on back as of cheque" , "Give one's sanction to" , "Put penalty points on (a driving licence)" .)