sim·mer / ˈsimər/ • v. [intr.] (of water or food) stay just below the boiling point while being heated: the goulash was simmering slowly in the oven | fig. the disagreement simmered for years and eventually boiled over. ∎  [tr.] keep (something) at such a point when cooking or heating it: simmer the sauce gently until thickened. ∎  be in a state of suppressed anger or excitement: she was simmering with resentment. ∎  (simmer down) become calmer and quieter.• n. [in sing.] a state or temperature just below the boiling point: bring the water to a simmer.

simmer XVII. Later form of (dial.) †simper (XV), perh. of imit. orig.; see -ER4.

simmer A method of cooking in water slightly below boiling point (also known as coddling).