Strained sound of rebuke muffling answer (4)
I believe the answer is:
taut
'strained' is the definition.
(I've seen this in another clue)
'sound of rebuke muffling answer' is the wordplay.
'sound of rebuke' becomes 'tut' (I've seen this in another clue).
'muffling' indicates putting letters inside.
'answer' becomes 'a' (abbreviation eg in Q and A).
'tut' enclosing 'a' is 'TAUT'.
(Other definitions for taut that I've seen before include "seaworthy" , "Held in tension" , "Stretched, pulled tight" , "Tightly drawn" , "Fully stretched" .)