No time for stifling expression of disgust, revealing nothing (6)
I believe the answer is:
nought
'nothing' is the definition.
('nought' can be a synonym of 'zero')
'no time for stifling expression of disgust' is the wordplay.
'time for' becomes 't' (I've seen this in other clues).
'stifling' means one lot of letters goes inside another.
'expression of disgust' becomes 'ugh' (I've seen this before).
'no'+'t'='not'
'not' enclosing 'ugh' is 'NOUGHT'.
'revealing' acts as a link.
(Other definitions for nought that I've seen before include "Zero" , "Go hunt for nothing" , "duck" , "The figure 0" , "The digit 0" .)