The word "kettle" refers to a simple household item used for boiling water, but there are several synonyms one can use to refer to it. A "teapot" is a synonym for kettle, but it is typically used to boil water for making tea. A "boiler" is another synonym for kettle and usually refers to large, industrial-sized machines used for heating water or generating steam. You can also use the word "cauldron" as a synonym for kettle, but this is typically used to refer to large cooking pots rather than tea kettles. Other synonyms for kettle include "samovar," "urn," and "hot pot." Overall, while the word "kettle" is the most common term, several synonyms can be used depending on the context.