noun

• (cooking) A vessel for boiling a liquid or cooking food, usually metal and equipped with a lid.
  "To cook pasta, you first need to put the kettle on."
• (geology) A kettle hole, sometimes any pothole.
• (ornithology, collective) A group of raptors riding a thermal, especially when migrating.
  "a kettle of hawks"
• (rail transport, slang) A steam locomotive

verb

• (originally British, of the police) To contain demonstrators in a confined area.
  "Life for senior officers has been made much easier by the use of counter-terrorism powers, which enable them to contain demonstrators for hours in a confined spot. This tactic, known as kettling, is seen by some as an attempt to prevent people lawfully demonstrating."
• (intransitive) Of a boiler: to make a whistling sound like the boiling of a kettle, indicative of various types of fault.