Slang phrase nigger in the woodpile "a hid motive or unknown factor impacting a condition within an adverse way" [OED 1989] is attested by 1800; Thornton's "American Glossary" (1912) defines it as "A method of accounting to the disappearance of gas," that's why "an unsolved thriller.The slang expression "Niga" is really a really offensive word that