Possible Definitions:
1. Cracker (n.) One who, or that which, cracks.
2. Cracker (n.) A noisy boaster; a swaggering fellow.
3. Cracker (n.) A small firework, consisting of a little powder inclosed in a thick paper cylinder with a fuse, and exploding with a sharp noise; -- often called firecracker.
4. Cracker (n.) A thin, dry biscuit, often hard or crisp; as, a Boston cracker; a Graham cracker; a soda cracker; an oyster cracker.
5. Cracker (n.) A nickname to designate a poor white in some parts of the Southern United States.
6. Cracker (n.) The pintail duck.
7. Cracker (n.) A pair of fluted rolls for grinding caoutchouc.