cracker

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 prawn cracker.
3. The final section of certain whips, which is made of a short, thin piece of unravelled rope, or which is a short piece of twisted string tied to the end of the whip, which produces a distinctive cracking sound when the whip is cracked.
4. A firecracker.
5. A Christmas cracker.
6. A person or thing that breaks a thing (e.g., nutcracker). · a lobster and crab shell cracker
7. Refinery equipment used to pyrolyse organic feedstocks. If catalyst is used to aid pyrolysis it is informally called a cat-cracker
8. One who cracks (i.e. overcomes) computer software or security restrictions.

Plural crackers