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.