1A kettle of tinned iron.
Generally regarded as of inferior quality, or typical of a poor household.
2A metal kettle, pan, etc., that is beaten to make a cacophonous noise, either in celebration or to show opprobrium, especially on the part of a large group of people. Compare "tin pan". Now chiefly historical.
3rare Extended and allusive uses. A piano of poor quality.
Late 17th century; earliest use found in William King (1663–1712), writer. From tin + kettle.