cracker

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A thin crisp wafer or biscuit, usually made of unsweetened dough.
• noun One that cracks, especially.
• noun A firecracker.
• noun A small cardboard cylinder covered with decorative paper that holds candy or a party favor and pops when a paper strip is pulled at one or both ends and torn.
• noun The apparatus used in the cracking of petroleum.
• noun One who makes unauthorized use of a computer, especially to tamper with data or programs.
• noun Offensive Used as a disparaging term for a white person, especially one who is poor and from the southeast United States.

from The Century Dictionary.

• noun One who or that which cracks or breaks (transitively).
• noun One who or that which cracks (intransitively).
• noun A boast; a lie.
• noun A thin hard or crisp biscuit.
• noun A bird, the pintail duck, Dafila acuta.
• noun plural The parrots as an order, Enucleatores.
• noun One of an inferior class of white hill-dwellers in some of the southern United States, especially in Georgia and Florida.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who, or that which, cracks.
• noun obsolete A noisy boaster; a swaggering fellow.
• noun A small firework, consisting of a little powder inclosed in a thick paper cylinder with a fuse, and exploding with a sharp noise; -- usually called firecracker.
• noun A thin, dry biscuit, often hard or crisp.
• noun A nickname to designate a poor white in some parts of the Southern United States.
• noun (Zoöl.) The pintail duck.
• noun (Mach.) A pair of fluted rolls for grinding caoutchouc.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A dry, thin, crispy, and usually salty or savory biscuit.
• noun 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.
• noun A firecracker.
• noun A person or thing that cracks, or that cracks a thing (e.g. whip cracker; nutcracker).
• noun A Christmas cracker
• noun Refinery equipment used to pyrolyse organic feedstocks. If catalyst is used to aid pyrolysis it is informally called a cat-cracker
• noun chiefly UK A fine thing or person (crackerjack).
• noun An ambitious or hard-working person (i.e. someone who arises at the 'crack' of dawn).
• noun computing One who cracks (i.e. overcomes) computer software or security restrictions.
• noun obsolete A noisy boaster; a swaggering fellow.
• noun The pintail duck.
• noun obsolete A pair of fluted rolls for grinding caoutchouc.
• noun US, pejorative, ethnic slur An impoverished white person from the southeastern United States, originally associated with Georgia and parts of Florida; by extension: any white person.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a thin crisp wafer made of flour and water with or without leavening and shortening; unsweetened or semisweet
• noun a programmer who cracks (gains unauthorized access to) computers, typically to do malicious things
• noun firework consisting of a small explosive charge and fuse in a heavy paper casing
• noun a party favor consisting of a paper roll (usually containing candy or a small favor) that pops when pulled at both ends
• noun a poor White person in the southern United States