Sword bears being twisted (5)
I believe the answer is:
sabre
'sword' is the definition.
(I know that sabre is a type of sword)
'bears being twisted' is the wordplay.
'being twisted' is an anagram indicator.
'bears' with letters rearranged gives 'SABRE'.
(Other definitions for sabre that I've seen before include "Bares (anag.)" , "Sword with curved blade" , "Large wasp" , "Walt --, cartoonist" , "Heavy cavalry sword" .)