knell (n.) Look up knell at Dictionary.com
Old English cnyll "sound made by a bell when struck or rung slowly," from knell (v.). Compare Dutch knal, German knall, Danish knald, Swedish knall. The Welsh cnull "death-bell" appears to be a borrowing from English. For vowel evolution, see bury. For pronunciation, see kn-.
knell (v.) Look up knell at Dictionary.com
Old English cnyllan "to toll a bell; strike, knock," cognate with Middle High German erknellen "to resound," Old Norse knylla "to beat, thrash;" probably imitative. Intransitive sense, in reference to a bell, is from late 14c. Related: Knelled; knelling.