Heavy glove (8)
I believe the answer is:
gauntlet
'heavy glove' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for gauntlet that I've seen before include "It may be thrown down or run" , "Handy thing to take up" , "Throw it down to offer a challenge" , "Metal glove of medieval soldiers" , "Throw this glove down as a challenge" .)