death knell
noun
1.
a harbinger of the end, death, or destruction of something.
2.
passing bell
.
British Dictionary definitions for
death knell
death knell
noun
1.
something that heralds death or destruction
2.
a bell rung to announce a death
Idioms and Phrases with
death knell
death knell
Something that indicates impending failure, as in
His low scores sounded the death knell for his ambitions
. The noun
knell
, used for the ringing of a bell since at least
a.d.
1000, is rarely heard today except in this figurative phrase.