deader

deader than a doornail

Definitively, undeniably dead. (Doornails were hammered in a such a way that they could not be reused.) I poked that squirrel with a stick and, yeah, it's deader than a doornail.
See also: deader, doornail
Farlex Dictionary of Idioms.

*dead as a dodo

 and *dead as a doornail; deader than a doornail
dead; no longer in existence. (*Also: as ~.) That silly old idea is dead as a dodo. When I tried to start my car this morning, I discovered that the battery was deader than a doornail.
See also: dead, dodo
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

dead as a dodo

BRITISH
If something is as dead as a dodo, it is no longer active or popular. The foreign exchange market was as dead as a dodo. Note: The dodo was a large flightless bird that lived on the islands of Mauritius and Réunion. It became extinct in the late 17th century as a result of hunting and the destruction of its nests by pigs belonging to settlers on the islands.
See also: dead, dodo
Collins COBUILD Idioms Dictionary, 3rd ed.

dead as a (or the) dodo

1 no longer alive. 2 no longer effective, valid, or interesting. informal
The name dodo comes from Portuguese duodo meaning ‘simpleton’. It was applied to the large flightless bird of Mauritius because the bird had no fear of man and so was easily killed, being quickly wiped out by visiting European sailors. The dodo's fate has made it proverbial for something that is long dead and the name has been used metaphorically for an old-fashioned, stupid, or unenlightened person since the 19th century.
2000 John Caughie Television Drama The once pleasant family hour is now as dead as a dodo.
See also: dead, dodo
Farlex Partner Idioms Dictionary
See also:
  • deader than a doornail
  • doornail
  • (as) dead as a doornail
  • as dead as a doornail
  • dead as a doornail
  • be (as) dead as a doornail
  • (as) dead as a herring
  • herring
  • door
  • (as) dead as mutton
References in periodicals archive
The Clinton health-care plan is deader than Elvis."
Righter than thou: in the Republican presidential race, extremism is the norm
"Color overall in glassware is deader than a door nail," said one tabletop buyer.
U.S. tabletop buyers at Ambiente find high Euro fashion at a price
That's the way it was in the old days when the dogs and whips were masters, and that's the way it is today when we got stuff in the water and the air we can't even see that can kill us deader than we ever thought we could die.
Black, brown, red, and poisoned
Dieffenbachia trees, notably one big-eared Amoena, read over my shoulder, Outside, all id deader than a frosted doorknob, but here is our winter greenhouse, the stove fire roars and crackles, happy for the extra oxygen.
The greenhouse effect: too much oxygen can be a dangerous thing
Claims based on oral promises are "deader than a doornail," he says.
Is your lender liable?
Time was when many film buffs dismissed local action movies as being 'deader than a dodo bird,' permanently done in by overaged action superstars and their smug producers' failure to keep viewers excited and dynamically entertained.
Lights, camera, action-local action-dramas are finally making a comeback
Audi A4 Audi A4 > Cheap and |Cheerful Although it's a company that's now deader than a dead thing, Saab got their 9-3 very right towards the end of its life.
of with a tends to come of with a tends to come Used Car Guide Buying a compact executive Andy Andy; Buying a compact executive
Not surprisingly there are blown-out blow-dries and cancelled cut and colour appointments all over the place and it's not long before Blades is deader than Ian's dust-gathering restaurant - remember that place?
Dean hits a dead Ender; Furious Mick wreaks revenge on little brother for sick attack on wife Linda
This astonished Bo, because it contradicted his notion of shotshell ballistics, common among Americans: More shot equals "deader" birds.
More hits less shot: matching the load and choke has never been easier. Here's how to do it
The age of ideas is deader than a badger caught in a culler's sight.
Badgered into protesting
leader of Liberty Party Hrant Bagratyan - 2.15% or 31,643, the deader of National Self- Determination Union Paruyr Hayrikyan - 1.23%
Representatives of Raffi Hovhannisian: Protest actions will be continued
soap is dead.It's deader than the look in Jeremy Kyle's eyes.
The plot sickens
Back home in Pennsylvania, February and March make up the proverbial "dead of winter," and this year has been deader than most; unusually cold and snowy.
A season of new life and new dreams
The .375/06 JDJ with a 270 grain at 2,400 fps won't kill a deer any deader but will be entirely adequate for Elk at that distance--at the expense of moderately heavy recoil and heavy muzzle blast.
Long-range
ITV's defibrillator Simon Cowell (without him the channel would be even deader on it's a**e than it already is) must have more tricks up his sleeves to keep things moving.
Si's scream factor; THE WISE MAN OF TV