\Sim"mer\, v. i. [imp. & p. p. {Simmered}; p. pr. & vb.
n. {Simmering}.] [Prov. E. 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.                                 --Palsgrave.

\Sim"mer\, v. t.
To cause to boil gently; to cook in liquid heated almost or
just to the boiling point.