- to remain at or just below the boiling point, usually forming tiny bubbles with a low, murmuring sound
- to be about to break out, as in anger, revolt, etc.
Origin of simmerearlier simper from Late Middle English simperen: origin, originally echoic
- to keep (a liquid) at or just below the boiling point
- to cook in such a liquid
- to condense by simmering, as a liquid
- to become calm; cool off