Blade, black, changing hands (5)
I believe the answer is:
sabre
'blade' is the definition.
(sabre is a kind of blade)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for sabre that I've seen before include "Type of sword" , "Sword (that may be rattled)" , "Slasher" , "Bares (anag.)" , "weapon" .)