https://www.upworthy.com/origin-of-dead-as-a-doornail/
The fascinating origin of the phrase "dead as a doornail" - Upworthy
Feb 18, 2026 - Why do we say "dead as a doornail" and not just "dead as a nail"? This helpful video gives and explanation as well as a demonstration of deadnailing.
as afascinatingoriginphrasedead