Arm rest? (5)
I believe the answer is:
sling
'arm rest?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sling that I've seen before include "ballistic weapon" , "Keeping afloat" , "attached to a rifle, perhaps" , "Catapult or support as for injured arm" , "American drink" .)