A broom or sweep.
For I will rise up against them, saith the LORD of hosts, and cut off from Babylon the name, and remnant, and son, and nephew, saith the LORD. I will also make it a possession for the bittern, and pools of water: and I will sweep it with the BESOM of destruction, saith the LORD of hosts. ( Isaiah 14:22-23 )
Bibliography Information"Entry for 'Besom'". A King James Dictionary.