a container or device in which water is boiled, having a lid, spout, and handle

a depression in the ground thought to have been formed by the melting of an ice block trapped in glacial deposits, especially one that is circular and deep

our lake is probably a kettle

a kettle pond

a small area in which demonstrators or protesters are confined by police seeking to maintain order during a demonstration

activists in the kettle were protesting at being held and resisting arrest

(of the police) confine (a group of demonstrators or protesters) to a small area, as a method of crowd control during a demonstration

the plan was to get as close to the protest as possible without getting kettled