Primitive weapon (8)
I believe the answer is:
blowpipe
'primitive weapon' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for blowpipe that I've seen before include "Weapon shooting darts" , "Tube through which poisoned darts are propelled" , "Missile launcher" , "Tube through which a poisoned dart may be shot" , "Dart launcher" .)