death knell

idiomPart ofdeath

death knell — idiom

1. an event or sign that marks the end or failure of something

1.idiom
Definition

an event or sign that marks the end or failure of something

Example

The invention of the smartphone sounded the death knell for the simple flip phone that could only make calls and send texts.

The leak of the company's financial problems rang the death knell for any hope of getting a bank loan.