The old man was dead as a doornail.
那老头已经直挺挺地死了。
Be careful with that bottle. It's cyanide. One swallow of that and you'd be dead as a doornail.
当心那个瓶子, 那是氰化物。只要喝上一口, 就会叫人一命呜呼。
The treaty may be considered to be as dead as a doornail.
这项条约可以认为是完全作废了。
