- simmer (v.)
- 1650s, alteration of simperen "to simmer" (late 15c.), possibly of imitative origin. Figurative sense, of feelings, "to be agitated" is from 1764. Opposite sense, in simmer down, first recorded 1871.
I must and will keep shady and quiet till Bret Harte simmers down a little. [Mark Twain, letter, 1871]
Related: Simmered; simmering.