nigger

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

• noun Used as a disparaging term for a black person.
• noun Used as a disparaging term for a member of any dark-skinned people.
• noun Used as a disparaging term for a member of any socially, economically, or politically deprived group of people.

from The Century Dictionary.

• noun Same as niggard, 2.
• To burn (logs already charred or left unconsumed by former fires): with off: also, to burn (a log) in two in the middle.
• To exhaust (soil or land) by working it year after year without manure: with out.
• noun A black man; a negro.
• noun A native of the East Indies or one of the Australian aborigines.
• noun A black caterpillar, the larva of Athalia centifolia, the turnip saw-fly.
• noun A. kind of holothurian common off the coast of Cornwall, England: so called by Cornish fishermen.
• noun A steam-capstan on some Mississippi river boats, used to haul the boat over bars and snags by a rope fastened to a tree on the bank.
• noun A strong iron-bound timber with sharp teeth or spikes protruding from its front face, forming part of the machinery of a sawmill, and used in canting logs. etc.
• noun An impurity in the covering of an electrical conductor which serves to make a partial short circuit, and thus becomes sufficiently heated to burn and destroy the insulation.

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

• noun Low, deprecatory, and vulgar A negro; -- in vulgar derision or depreciation. It is usually intended and interpreted as highly insulting and vulgar.

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

• noun offensive, ethnic slur A dark-skinned person, especially a person of, or primarily of, Negro descent; a black person.
• noun offensive, ethnic slur, vulgar slang A person of Negro descent who acts in an unapproved manner, usually as an archetypical badass.
• noun African American Vernacular Informal term of address.
• verb transitive, dated To clear land by laying light pieces of round timber across the trunks of the trees and setting fire to them at the point of contact, by which means the trees are slowly burned through.
• verb intransitive, offensive To behave as a stereotypical black person.
• verb uncommon, transitive, offensive To treat as inferior.

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

• noun (ethnic slur) extremely offensive name for a Black person