knellEnglishOxford American Thesaurusknell noun 1 the knell of the ship's bell: toll, tolling, ringing, chime, clang, dong, peal, stroke, resounding, reverberation, clangor, boom; death knell; archaic knoll, tocsin. 2 the decision will probably toll the knell for the facility: end, beginning of the end, presage of the end, death knell; death sentence, death warrant; omen, evil omen, ill omen, portent, warning.