Many have spoken of such a victory (5)
I believe the answer is:
moral
'such a victory' is the definition.
I can't judge whether this definition defines the answer.
'many have spoken' is the wordplay.
'many' becomes 'm' (Roman numeral for a thousand).
'have' is a charade indicator (letters next to each other).
'spoken' becomes 'oral' (similar in meaning).
'm'+'oral'='MORAL'
'of' is the link.
Can you help me to learn more?
(Other definitions for moral that I've seen before include "Lesson that can be drawn from a story" , "Relating to principles of right and wrong" , "Behaving ethically" , "Virtuous and principled" , "Lesson offered by story" .)