canary

noun15

1. •
   A small, usually yellow, finch (genus Serinus), a songbird native to the Canary Islands.
2. •
   Any of various small birds of different countries, most of which are largely yellow in colour.
3. •
   Any test subject, especially an inadvertent or unwilling one. (From the mining practice of using canaries to detect dangerous gases.)
4. •
   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.
5. •
   A change that is tested by being rolled out first to a subset of machines or users before rolling out to all.
6. •
   (slang) An informer or snitch; a squealer.
7. •
   A light, slightly greenish, yellow colour.
8. •
   A light, sweet, white wine from the Canary Islands.

   • Ile to my honest knight sir Iohn Falstaffe, / And drinke Canary with him. — 1597
9. •
   A lively dance, possibly of Spanish origin (also called 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, […] — 1604
10. •
    (slang) A (usually yellow) capsule of the short-acting barbiturate pentobarbital/pentobarbitone (nembutal).
11. •
    (informal) A female singer, soprano, a coloratura singer.
12. •
    (Australia, informal) A yellow sticker applied by the police to a vehicle to indicate it is unroadworthy.

    • 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. — 1999
13. •
    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. — 2022
14. •
    (slang, no longer used) A sovereign (coin).
15. •
    (slang, no longer used) A prisoner or convict.

verb3

1. •
   To test a software change by rolling out to a small set of machines or users before making it available to all.
2. •
   (slang) To inform or snitch, to betray secrets, especially about illegal activities.
3. •
   To dance nimbly (as in the canary dance).

adjective1

1. •
   Of a light yellow colour.

adjective1

1. •
   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. — 2005

noun1

1. •
   Someone connected with Norwich City Football Club, as a fan, player, coach etc.