canary

noun:

1. A (usually yellow) capsule of the short-acting barbiturate pentobarbital/pentobarbitone (Nembutal).
2. Any of various small birds of different countries, most of which are largely yellow in colour.
3. A lively dance, possibly of Spanish origin (also called canaries).
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 light, slightly greenish, yellow colour.
6. An informer or snitch; a squealer.
7. A light, sweet, white wine from the Canary Islands.
8. A yellow sticker of unroadworthiness.
9. Someone connected with Norwich City Football Club, as a fan, player, coach etc.
10. Any test subject, especially an inadvertent or unwilling one. (From the mining practice of using canaries to detect dangerous gases.).
11. A small, usually yellow, finch (genus Serinus), a songbird native to the Canary Islands.
12. A female singer, soprano, a coloratura singer.

adjective:

1. That can be exercised on quarterly dates, a set time period (usually one year) after the issue date, and before the expiry date.
2. Of a light yellow colour.

verb:

1. To inform or snitch, to betray secrets, especially about illegal activities.
2. To dance nimbly (as in the canary dance).