Kessel

a solid metal container or pot, often large, used to boil liquids: a kettle, cauldron, boiler, etc.

an area in which the enemy (or game) is encircled; a pocket or besieged area (by extension also the siege itself)

"der Kessel von Stalingrad"

ellipsis of Polizeikessel: kettling, a police tactic to surround and contain demonstrators

the lair of certain animals such as fox, badger, rabbit, and wild boar