Is there a single word to describe the canary in the phrase "Canary in a coalmine"? The best I can come up with is sentinel, but I'm nearly positive there's a more precise option.

Edit: To clarify I'm not looking for words that describe the canary but rather for a word the encapsulates the entire phrase. That is, I don't want to finish the phrase "the canary is a ...". I do want to finish the phrase "$PERSON was a ..." where the blank implies as many of the attributes of the proverbial canary as possible (e.g. going down the dangerous road first, warning those that follow, connotations of captivity, &c). I'm reluctant to use the phrase, or "canary" as it strikes me too colloquial/lighthearted for the work at hand.

@senex suggestion of bellwether and @bib suggestion of tocsin are closest to what I'm looking for thusfar.

  • 4
    what aspect of the canary are you trying to capture? sentinel certainly applies. So does expendable
    – Jim
    Commented Aug 8, 2014 at 4:07
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    "telltale" as adjective or noun.
    – Kai Carver
    Commented Aug 8, 2014 at 4:12
  • 3
    Alarm is closer to the idea of the canary than 'sentinel.' syn. warning device - a device that signals the occurrence of some undesirable event thefreedictionary.com/warning+device
    – Kris
    Commented Aug 8, 2014 at 5:35
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    If you are asking two questions, as it appears you are, you need to split them into separate requests. Commented Aug 8, 2014 at 8:15
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    I just came to this question through the "Hot Network Questions", and wanted to post this relevant recent Buttersafe: buttersafe.com/2014/07/29/a-bird-holds-its-breath
    – gla3dr
    Commented Aug 8, 2014 at 16:11

15 Answers 15


Consider tocsin

A warning; an omen. [American Heritage Dictionary]

It also means alarm but the ominous quality makes it appealing in this case.

  • I like this - I had a word on the tip of my tongue when I asked this question and I'm 90% sure this was it! Given the activity, forgive me if I leave it open another day or two before accepting. Commented Aug 8, 2014 at 16:36

The canary is a telltale, "something that indicates or reveals information" or "a device that indicates or registers information".

Example in the news: "Tiny wireless sensing device alerts users to telltale vapors remotely". The word can be used as a noun or adjective.

  • 4
    Love the description of a canary as a 'wireless sensing device'. +1 for that
    – Ian Lewis
    Commented Aug 8, 2014 at 15:25
  • +1 Telltales are also used on sails. They show the point where you've trimmed (or eased) the sail too far relative to your wind. This is a very good analogy to the canary. Commented Aug 11, 2014 at 7:16

Bellwether, I believe, would be appropriate for such a use.


  • The leading sheep of a flock, with a bell on its neck.
  • An indicator or predictor of something. "college campuses are often the bellwether of change"

synonyms: harbinger, herald, indicator, predictor

From: oxforddictionaries.com

  • 3
    I'd bet that 99 out of a 100 times you use this word, people will ask, "a what?" What's a "bellwether". This is not at all a common term.
    – Octopus
    Commented Aug 8, 2014 at 20:24
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    @octopus My formal education consisted of high school, and nothing more; moreover, in my graduating class I was ranked just above the class goat. Nevertheless, I managed to acquire the word "bellwether." The word must have have come up in the course of reading, a much loved activity of mine. Reading is the key to the acquisition of interesting words. One should not write if he is afraid of occasionally driving his readers to consult a dictionary. Commented Aug 9, 2014 at 0:51
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    Apart from the obscurity, bellwether carries no connotation of warning - it's simply a leader.
    – peterG
    Commented Aug 10, 2014 at 2:57
  • @peterG \\ If the bellwether were to predict some future event that you would consider to be undesirable, how could you say that you were not warned? Commented Aug 10, 2014 at 3:43
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    Financial reporters frequently use this word.
    – Barmar
    Commented Aug 11, 2014 at 18:53

I think just "Canary" can be used here, this usage has become so common when one says canary people will understand that you refer to this meaning. Have a look at usage 6 here http://en.wiktionary.org/wiki/canary


The canary is acting as a guinea pig, in that term's sense, “A living experimental subject” [wiktionary]. The term lab rat has a similar sense. (Also see What's another word for Guinea Pig, i.e. when you call someone a "test dummy"?.)

You might also consider the term point man, in its sense “the soldier who takes point; the soldier who assumes the first and most exposed position in a combat military formation; the lead soldier/unit advancing through hostile or unsecured territory”. This term also appears in wiktionary's example for use of the previously-mentioned word expendable:

Private Johnson was afraid the Lieutenant considered him an expendable, since he was always picked as point man.

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    The canary is by no means a guinea pig, since miners never used the bird to experiment. They were not taking the birdie down the mine thinking "gosh, let's see what happens if we expose a living being to dangerous gas" — they knew beforehand what would happen. I do agree with expandable, though that applies to the canary and the lab rat alike.
    – oerkelens
    Commented Aug 8, 2014 at 7:09
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    That should have been expendable of course... Let's not go down the path of expandable canaries :(
    – oerkelens
    Commented Aug 8, 2014 at 7:23
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    @oerkelens They are experimenting though: the hypothesis is just "Let's see if this particular mine is deadly" rather than "let's see if gas is deadly" Commented Aug 8, 2014 at 10:46
  • @Yamikuronue The question is not if but when. It's not an experiment, it's a threshold.
    – orange80
    Commented Aug 9, 2014 at 7:55
  • Point is the guy who trips the Claymore. I like this.
    – KalleMP
    Commented Jun 1, 2016 at 17:14

Depending on your context, I would suggest Scout, Vanguard, or Pawn.


A person sent out ahead of a main force in order to gather information.

This usage fits the notion of a "canary in a coal mine" because the canary is an active information source for those carrying it.


The forefront of an advancing army.

Usually, the vanguard occupies the most precarious position in a battle. They can report on enemy positions, strengths, etc., as a Scout might, but they are meant to actively engage in the combat. And, as the "first on the scene" they have the potential of suffering high casualty rates.


A person used by others for their own purposes. In chess, a piece of low value, often sacrificed for better position or to gain tempo.

In my mind, a Pawn is a combination of Scout and Vanguard, and perhaps the closest to the general role of the canary. The pawn, like the canary, is often a victim of circumstance whose well being is certainly not under its own control.

  • Similar to vanguard is the avant-garde. Whether you think of armies or art when you hear it says a heck of a lot.
    – Pharap
    Commented Aug 9, 2014 at 3:47
  • I also like vanguard as it is the guy hoping to draw enemy fire (poor guy).
    – KalleMP
    Commented Jun 1, 2016 at 17:15


A person or thing that foreshadows or foretells the coming of someone or something.

It really depends on what you trying to communicate, but a person, who does some of the things are allude to, depending on the context, may be referred to as a "harbinger".

  • Harbinger, though, as you say foretells, but it also carries the sense of being in some way part of what's to come; a small cloud as a harbinger of a storm, for instance. It doesn't carry the idea of a test in the way the canary does. Or, the death of the canary could be the harbinger of the miners demise; but the canary itself - no.
    – peterG
    Commented Aug 10, 2014 at 3:02
  • Agreed. However, the poster didn't really give much in the way of context, so... It would be easier if we knew exactly what they end use was. Commented Aug 25, 2014 at 21:28

A litmus test?

enter image description here

A litmus test is a piece of paper that is dipped in a solution to test whether the liquid is basic or acidic.

It has come to mean any general test to immediately test some condition.

Whether I can I summarise the candidate's core strengths within two minutes of reading his CV, became my litmus test of whether I would consider him for the position or not.

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    This is not a good example. Litmus paper can be reused! Canaries can only die once. Big difference!
    – Mr Lister
    Commented Aug 8, 2014 at 9:33
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    @MrLister once the Canary fell unconscious if you left the area with the bad air it could potentially revive...
    – Tim B
    Commented Aug 11, 2014 at 11:26

A canary in a coal mine is a kind of probe which is used to provide early warning or test something.

The original phrase originates from miners using caged canaries when they went down a potentially dangerous mine shaft. If the mine shaft contained dangerous amounts of gases such as methane or carbon dioxide, the canary would show signs of distress or die first, providing the miners with early warning to escape immediately. (See here and here.)

A newer use is in software development, where a "canary" version or "canary test" may be shipped to a market to test some new feature or other change to the software. Feedback from users will then be used to determine further actions. (See here.)

In summary, I would suggest that the single word probe is suitable in many cases.

  • Similarly, sensor. In fact, I prefer sensor over probe, as a probe is used to observe an area before committing more valuable resources to occupying it. A canary, on the other hand, is used to monitor an area which is already occupied in order to alert occupants to adverse changes in local conditions.
    – talrnu
    Commented Aug 8, 2014 at 14:51

In terms of the meaning of "one who announces danger" you could also use:

lookout, watchtower, harbinger, herald, augury

with lookout and watchtower having the extra connotation of staying in a given place to perform that duty, much like a canary in a mine would. "Harbinger" might have the effect you are looking for, as it is generally associated with the phrase "harbinger of death", which is what the canary was used as (if the canary died, it was due to lack of oxygen, and if the miners didn't get out of the mine quickly, they were next).


I suggest tripwire:

A wire stretched close to the ground, working a trap, explosion, or alarm when disturbed and serving to detect or prevent people or animals entering an area.

For a sample usage where "tripwire" is used to refer to an "early warning system", see the Lee Child/Jack Reacher book "Tripwire".

  • But a canary in a mine isn't intended to stop people entering an area, it detects an emerging threat.
    – Chenmunka
    Commented Aug 8, 2014 at 14:16
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    @Chenmunka I believe Chris means a canary is like a tripwire in that it acts as an indicator that an awaited event has occurred. Tripwires indicate when a person has walked into an area or position, and canaries indicate when the mine has become dangerous to work in.
    – talrnu
    Commented Aug 8, 2014 at 14:45
  • @talmu Exactly. Commented Aug 8, 2014 at 17:32
  • @talrnu but a tripwire has kind of opposite meaning, in terms of who gets an indication.
    – Michael
    Commented Aug 8, 2014 at 21:42
  • @Michael I don't think so. The people who set the tripwire get the alarm, so that they take appropriate action. Just like miners take the canaries down the coal mine, so they can get a warning and take appropriate action. (If an invader actually trips over the wire, they might get a warning as well, but that is not the purpose of the tripwire.) Commented Aug 8, 2014 at 22:23

I'd suggest, with some irony, cockatoo - informally used for "a lookout posted by those engaged in illegal activity".


I suggest 'fusebox'.

The purpose of the canary is that it dies before the humans do. This makes it a deliberately introduced failure point. So a good analogy is a domestic fusebox. This has fuses, delicate wires that fail in the event of a power surge thus protecting the more important electrical goods in the house.

I say 'fusebox' rather than 'fuse' because 'light the fuse' already has other connotations.


I suggest "precursor".

The phrase canary in a coal mine comes from an actual practice of taking a canary into teh mine shaft. If the canary died it meant there was carbon monoxide present and was a warning to leave for a better ventilated place.

A precursor is a thing or condition that comes before something malign. The components of the word signal its meaning. Pre means before; cursor denotes the malignity although its primary meaning in other contexts is not bad. (Just look at the pointy thing moving around on your computer screen)

  • I'm really not sure this is correct; precursor just means something that comes before something else. Doesn't mean it's bad. Why do you think cursor means bad?
    – Rob Grant
    Commented Aug 11, 2014 at 9:00
  • Cursor does not mean bad, but the root word denotes it:curse
    – piquet
    Commented Aug 12, 2014 at 3:09
  • That's not the root :) It comes from the Latin for forerunner. Curse is from old English.
    – Rob Grant
    Commented Aug 12, 2014 at 5:51

A canary in a mine can be thought of as an Oracle. In ancient times, the Oracle was an expendable entity to go to, to get any type of an alarm, or some type of alarming prediction.

From Wikipedia on Pythia:

The Pythia … was the name of any priestess throughout the history of Temple of Apollo at Delphi… the new priestess was selected after the death of the current priestess.

Some interesting history might include these Oracles were perhaps underground, or close to a source of toxic gas that gave them their "powers", and made them quite expendable according to some theories

I really like many of the answers here, but I suppose your choice depends on the exact context of the use of this word.

  • More like an alarm clock, I’d say.
    – tchrist
    Commented Aug 14, 2014 at 3:07
  • That's a good answer too, maybe a "rooster"? :)
    – unclepete
    Commented Aug 14, 2014 at 3:09
  • No, that would be an "alarm cock".
    – Hot Licks
    Commented Nov 4, 2014 at 17:40

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