Look embarrassed, like an unsuccessful matador (5)
I believe the answer is:
gored
'like an unsuccessful matador' is the definition.
(a matador might be gored by a bull)
'look embarrassed' is the wordplay.
'look' becomes 'go' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'embarrassed' becomes 'red' (someone may blush or go red when embarrassed).
'go'+'red'='GORED'
Can you help me to learn more?
(Other definitions for gored that I've seen before include "Injured by a horn or tusk" , "Stabbed with a horn/tusk" , "like an unfortunate matador?" , "Wounded by bull's horns" , "Wounded by a bull" .)