Agreed to manufacture gas-filled bomb (7)
I believe the answer is:
grenade
'bomb' is the definition.
(grenade is a kind of bomb)
'agreed to manufacture gas-filled' is the wordplay.
'to manufacture' indicates anagramming the letters.
'gas' becomes 'n' (I can't justify this - if you can you should believe this answer much more).
'filled' means one lot of letters goes inside another.
'agreed' with letters rearranged gives 'greade'.
'greade' placed around 'n' is 'GRENADE'.
Can you help me to learn more?
(Other definitions for grenade that I've seen before include "Hand-thrown bomb" , "Hand-thrown explosive" , "Small hand missile" , "Small explosive device" , "Missile thrown" .)