verb

1. To cook or undergo heating slowly at or below the boiling point.

   “The soup simmered on the stove.”

2. To cause to cook or to cause to undergo heating slowly at or below the boiling point.

   “Simmer the soup for five minutes, then serve.”

3. To be on the point of breaking out into anger; to be agitated.

Synonyms: coddle

noun

1. The act of something that simmers.