One who fought a dog trial unrestrainedly (9)
I believe the answer is:
gladiator
'one who fought' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'a dog trial unrestrainedly' is the wordplay.
'a dog trial' can be anagrammed to 'GLADIATOR'.
But, I'm unsure how this is indicated.
Can you help me to learn more?
(Other definitions for gladiator that I've seen before include "Film" , "Colosseum combatant" , "Professional combatant in ancient Rome" , "Man appearing in ring" , "One scrapped" .)