Definitions

1. verb

to cook or heat something, especially a liquid, at a low temperature, so that it is warm or hot but not boiling.

“She left the stew to simmer on low heat.”

2. verb

to be in a state of quiet but intense activity or emotion.

“He has been simmering with anger all day.”

3. noun

a gentle, low boil of a liquid, typically below 180°F (82°C).

“The pot was at a simmer, and the soup was ready to serve.”