Simmer
Simmer , intransitive verb
[Prov. English also simper; -- an onomatopoetic word.]
To boil gently, or with a gentle hissing; to begin to boil.
I simmer as liquor doth on the fire before it beginneth to boil.
Simmer , transitive verb
To cause to boil gently; to cook in liquid heated almost or just to the boiling point.