crackers

1. A dry, thin, crispy baked bread (usually salty or savoury, but sometimes sweet, as in the case of graham crackers and animal crackers).
2. A short piece of twisted string tied to the end of a whip that creates the distinctive sound when the whip is thrown or cracked.
3. A firecracker.
4. A person or thing that cracks, or that cracks a thing (e.g. whip cracker; nutcracker).
5. A Christmas cracker.
6. Refinery equipment used to pyrolyse organic feedstocks. If catalyst is used to aid pyrolysis it is informally called a cat-cracker
7. A fine thing or person (crackerjack).

   She's an absolute cracker!

8. An ambitious or hard-working person (i.e. someone who arises at the 'crack' of dawn).
9. One who cracks (i.e. overcomes) computer software or security restrictions.
10. A noisy boaster; a swaggering fellow.
11. (racial slur) An impoverished white person from the southeastern United States, originally associated with Georgia and parts of Florida; (by extension) any white person.
12. (Florida) A police officer.
13. A northern pintail, species of dabbling duck.
14. A pair of fluted rolls for grinding caoutchouc.

adjective

Crazy, insane.