Bound to admit blunder, if scared (9)
I believe the answer is:
terrified
'scared' is the definition.
(terrifying is a kind of scaring)
'bound to admit blunder if' is the wordplay.
'bound' becomes 'tied' (I've seen this before**).
'to admit' means one lot of letters goes inside another.
'blunder' becomes 'err' (I've seen this before).
'err'+'if'='errif'
'tied' enclosing 'errif' is 'TERRIFIED'.
(Other definitions for terrified that I've seen before include "Panic-stricken - dire refit (anag)" , "Greatly frightened" , "Scared stiff" , "Extremely frightened" .)