Weaponry for a mother trapped in lease (8)
I believe the answer is:
armament
'weaponry' is the definition.
(armament is a kind of weaponry)
'a mother trapped in lease' is the wordplay.
'mother' becomes 'mam' (I've seen this in other clues).
'trapped in' means one lot of letters goes inside another.
'lease' becomes 'rent' ('rent' can be a synonym of 'lease').
'mam' going inside 'rent' is 'rmament'.
'a'+'rmament'='ARMAMENT'
'for' is the link.
(Other definitions for armament that I've seen before include "Equipping for war" , "Weaponry" , "The providing of weapons" , "Munitions" .)