dead as a doornail

The phrase "dead as a doornail" is an idiomatic expression referring to something or someone that is completely, irreversibly dead or lifeless. It suggests a state of being inanimate and devoid of any signs of life, similar to a doornail, which has no vitality or ability to move. This phrase is often used to emphasize the finality and absolute lack of any potential for revival or resuscitation.