n. [ OE. knel, cnul, AS. cnyll, fr. cnyllan to sound a bell; cf. D. & G. knallen to clap, crack, G. & Sw. knall a clap, crack, loud sound, Dan. knalde to clap, crack. Cf. Knoll, n. & v. ] The stroke of a bell tolled at a funeral or at the death of a person; a death signal; a passing bell; hence, (figuratively), a warning or harbinger of, or a sound indicating, the passing away of anything; -- also called death knell. [ 1913 Webster +PJC ]

The dead man's knell
Is there scarce asked for who. Shak. [ 1913 Webster ]

The curfew tolls the knell of parting day. Gray. [ 1913 Webster ]

v. i. [ imp. & p. p. Knelled p. pr. & vb. n. Knelling. ] [ OE. knellen, knillen, As. cnyllan. See Knell, n. ] To sound as a knell; especially, to toll at a death or funeral; hence, to sound as a warning or evil omen. [ 1913 Webster ]

Not worth a blessing nor a bell to knell for thee. Beau. & Fl. [ 1913 Webster ]

Yet all that poets sing, and grief hath known,
Of hopes laid waste, knells in that word, “alone”. Ld. Lytton. [ 1913 Webster ]

v. t. To summon, as by a knell. [ 1913 Webster ]

Each matin bell, the baron saith,
Knells us back to a world of death. Coleridge. [ 1913 Webster ]