You might look in a better fargin’ dictionary. Sure, the origin of “niggard” is unclear, but not its timeline, which predates the N-word in the English language by a couple hundred years at least. “Niggard” comes up as early as Chaucer, late 14th century. The most commonly speculated origin is Scandanavian nig/Old Norse hnoggr, meaning miserly. Don’t know how much faith you want to put in Indo-European roots, but one meaning of the root ken- is conjectured to relate a family of words with a connotation implying closing, tightening, or pinching (the family of related words is hypothesized to include such n-words as nap, nibble, nod, nosh, neap, nip). The racial slur “nigger,” on the other hand, doesn’t enter the lexicon until the 1500’s, first as “neger” or “neeger,” obviously from the same root as the French negre and Spanish negro, words for the color black, which are derived from the Latin niger.