At liberty to use weapon being self-governing (9)
I believe the answer is:
freelance
'self-governing' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I don't see?
'at liberty to use weapon' is the wordplay.
I cannot really see how this works, but
'weapon' could be 'lance' (lance is a kind of weapon) and 'lance' is located in the answer.
'at liberty' could be 'free' (similar in meaning) and 'free' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'being' acts as a link.
Can you help me to learn more?
(Other definitions for freelance that I've seen before include "not regularly employed" , "Self-employed worker for hire" , "Not tied to employer" , "Self-employed person offering services where needed" , "without regular work?" .)