A bit tired and angry (3)
I believe the answer is:
red
'angry' is the definition.
(someone may go red when angry)
'a bit tired and' is the wordplay.
'a bit' says the answer is hidden in the clue (I've seen 'bit of' mean this).
'RED' is hidden in the letters of 'tired and'.
(Other definitions for red that I've seen before include "The colour of the former Russian army" , "Type of wine" , "Colour of a cardinal's hat" , "Crimson" , "Colour of communism" .)