canary

noun

1. (countable, uncountable)A small, usually yellow, finch (genus Serinus), a songbird native to the Canary Islands.
2. (countable, uncountable)Any of various small birds of different countries, most of which are largely yellow in colour.
3. (countable, informal, uncountable)A female singer, soprano, a coloratura singer.
4. (countable, slang, uncountable)An informer or snitch; a squealer.
5. (countable, uncountable)A light, slightly greenish, yellow colour.
6. (countable, slang, uncountable)A (usually yellow) capsule of the short-acting barbiturate pentobarbital/pentobarbitone (nembutal).
7. (Australia, countable, informal, uncountable)A yellow sticker applied by the police to a vehicle to indicate it is unroadworthy.

   “The tendency in these types of situations (as far as I can see) is that because I don't think the act itself is illegal, the police will go through your vehicle systematically loking^([sic]) for anything wrong with it, to slap a canary on it (that's slang for an unroadworthy sticker) or present you with some other fine.”

   “Yes, if the exhaust is to noisey^([sic]) they can slap a yellow canary on it, but the[n] who cares you got rid of it.”

   “You don't have to carry a spare wheel for a car to be roadworthy, and if you *do* carry one, it doesn't have to be in a roadworthy condition *unless* you fit it [to] the car and drive on it. / If it's not and you get pinched, expect a canary...”

8. (countable, uncountable)Any test subject, especially an inadvertent or unwilling one. (From the mining practice of using canaries to detect dangerous gases.)
9. (countable, uncountable)A value placed in memory such that it will be the first data corrupted by a buffer overflow, allowing the program to identify and recover from it.
10. (countable, uncountable)A change that is tested by being rolled out first to a subset of machines or users before rolling out to all.
11. (countable, uncountable)A light, sweet, white wine from the Canary Islands.

    “Ile to my honeſt knight ſir Iohn Falſtaffe, / And drinke Canary with him.”

    “And though the annals of the period do not show us that there was less ale drawn, or less canary called for; men got dry with the heat of polemical discussion, and drunk with a text, not the fag end of a ballad, in their mouths; and people made a sort of morality of straight hair, long faces, and sad-coloured garments.”

    “Or maybe you'd accept iv a couple o' bottles of claret or canaries?”

12. (countable, uncountable)A lively dance, possibly of Spanish origin (also called canaries).

    “In an other corner, Mistris Minx, a marchants wife, that will eate no cherries, forsooth, but when they are at twentie shillings a pound, that lookes as simperingly as if she were besmeard, and iets it as gingerly as if she were dancing the canaries, […]”

    “[…] I haue ſeen a medicine / That's able to breath life into a ſtone, / Quicken a rocke, and make you dance Canari / With ſprightly fire and motion, […]”

13. (UK, countable, obsolete, slang, uncountable)A sovereign (coin).
14. (countable, uncountable)A previously-issued ticket, retained by a ticket-seller, conductor or driver and resold to a subsequent passenger as a means of defrauding the transport company.

    “She had previously been sacked ... for "selling canaries" - a practice in which drivers resell used tickets to passengers and keep the fare for themselves.”

15. (UK, countable, obsolete, slang, uncountable)A prisoner or convict.
16. Someone connected with Norwich City Football Club, as a fan, player, coach etc.

adj

1. Of a light yellow colour.
2. (not-comparable)That can be exercised on quarterly dates, a set time period (usually one year) after the issue date, and before the expiry date.

   “Canary callable bonds are a type of step-up bond that is a hybrid structure, having elements of both Bermudan and European calls.”

   “The canary bond is unique in that it is callable during the period before the security converts to a noncallable or bullet structure; the canary callable coupon can possess a step-up feature.”

   “A (receiver) Canary swaption has two expiry dates 0 < θ₁ < θ₂ ≤ t₀ and involved two swaps Sⁱ (i = 1, 2) with cash -flows (t_(i,j), c_(i,j)) (1 ≤ j ≤ nᵢ).”

verb

1. (intransitive)To dance nimbly (as in the canary dance).

   “but to jig off a tune at / the tongue's end, canary to it with your feet,”

2. (slang)To inform or snitch, to betray secrets, especially about illegal activities.
3. To test a software change by rolling out to a small set of machines or users before making it available to all.