Set aside weapon carried in E-boat? (7)
I believe the answer is:
earmark
'set aside' is the definition.
('earmark' can be a synonym of 'set aside')
'weapon carried in e-boat?' is the wordplay.
'weapon' becomes 'arm' (I've seen this before).
'carried in' indicates putting letters inside.
'boat?' becomes 'ark' (ark is a kind of boat**).
'e'+'ark'='eark'
'arm' inserted inside 'eark' is 'EARMARK'.
(Other definitions for earmark that I've seen before include "spot where The Ring may be put on?" , "Designate for a specific purpose" , "Set specially aside" , "Set aside for later" , "Reserve for later use" .)