simmer

verb5

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. •
   (figurative) To be on the point of breaking out into anger; to be agitated.

   • Maybe that really did happen, and Robin's anger at his wife had simmered for this long? — 2006
4. •
   (figurative) To remain angry with someone or something past the point of exhaustion; to resign oneself to holding a grudge, especially after some failed attempts to resolve a situation.

   • I tried to get through to him; all that's left for me to do is simmer.
5. •
   (figurative) To develop gradually, of an idea or plan.

   • The idea for The Sims was one that had been simmering in Wright's mind for quite some time, and was initially conceived as an architecture simulation. — 2003

noun2

1. •
   The state or process of simmering.

   • The kettle was kept on the simmer.
2. •
   (informal) Someone who plays a sim (a simulation game), particularly The Sims.

noun1

1. •
   (slang) A fan of the video game series The Sims.