They’ll take position on the bridge without recourse to arms (5-3)
I believe the answer is:
pince-nez
'arms' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for pince-nez that I've seen before include "Pair of glasses that clip onto the nose" , "Nose-gripping specs" , "Spectacles clipped to the nose" , "Pair of glasses that clip on the nose, with no side-pieces" , "Glasses that clip onto nose without side-pieces" .)