One brought in weaponry with obligation to maintain constant truce (9)
I believe the answer is:
armistice
'truce' is the definition.
(synonyms)
'one brought in weaponry with obligation to maintain constant' is the wordplay.
I cannot quite see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
'weaponry' could be 'arms' (synonyms) and 'arms' is present in the leftover letters.
'constant' could be 'e' (mathematics: 2.71) and 'e' is present in the answer.
The remaining letters 'tic' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for armistice that I've seen before include "when shooting stops" , "let-up from war" , "Fire is prevented by this" , "harbinger of peace?" , "Suspension of hostilities" .)