Self-employed getting weapon for nothing (9)
I believe the answer is:
freelance
'self-employed' is the definition.
('freelance' can be a synonym of 'self-employed')
'getting weapon for nothing' is the wordplay.
'getting' means one lot of letters go next to another.
'weapon' becomes 'lance' (lance is a kind of weapon).
'for nothing' becomes 'free' (I've seen this before).
'lance' put after 'free' is 'FREELANCE'.
(Other definitions for freelance that I've seen before include "He works alone" , "Medieval mercenary" , "Not tied to employer" , "Independent" , "Self-employed person offering services where needed" .)