Republican tease traps back stabber (4)
I believe the answer is:
dirk
'back stabber' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for dirk that I've seen before include "Duncan's killer?" , "Highland dagger" , "Small dagger" , "which might get one stuck in Highlands" , "Dagger (belonging to Bogarde?)" .)