A bit embarrassed after being told to be quiet (5)
I believe the answer is:
shred
'a bit' is the definition.
(I've seen this before)
'embarrassed after being told to be quiet' is the wordplay.
'embarrassed' becomes 'red' (someone may blush or go red when embarrassed).
'after' is a charade indicator (letters next to each other).
'being told to be quiet' becomes 'sh' (sh is used to tell someone to be quiet).
'red' put after 'sh' is 'SHRED'.
(Other definitions for shred that I've seen before include "Dispose of" , "Scrap; finely tear" , "Cut into tiny pieces" , "Cut finely" , "Strip of material; a very small amount" .)