Cowardly cry: that hurt! (6)
I believe the answer is:
yellow
'cowardly' is the definition.
(similar in meaning)
'cry that hurt' is the wordplay.
'cry' becomes 'yell' (synonyms).
'that hurt' becomes 'ow' (I've seen this in other clues).
'yell'+'ow'='YELLOW'
(Other definitions for yellow that I've seen before include "Chicken" , "show sign of age" , "Flaxen" , "centre of egg" , "Colour of Malvolio's stockings (T. Night)" .)