The Collaborative International Dictionary of English v.0.48:

Niggard \Nig"gard\ (n[i^]g"g[~e]rd), n. [Icel. hn["o]ggr
   niggardly, stingy + -ard; cf. Sw. njugg, AS. hne['a]w.]
   A person meanly stingy and covetous; one who spends
   grudgingly; a stingy, parsimonious fellow; a miser.
   --Chaucer.
   [1913 Webster]

         A penurious niggard of his wealth.       --Milton.
   [1913 Webster]

         Be niggards of advice on no pretense.    --Pope.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Niggard \Nig"gard\, a.
   Like a niggard; meanly covetous or parsimonious; niggardly;
   miserly; stingy.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Niggard \Nig"gard\, v. t. & i.
   To act the niggard toward; to be niggardly. [R.] --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

niggard
    n 1: a selfish person who is unwilling to give or spend [syn:
         niggard, skinflint, scrooge, churl]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "niggard":
   Silas Marner, cheapskate, cheeseparing, churl, close, curmudgeon,
   grudging, mean, mingy, miser, miserly, muckworm, niggardly,
   penny pincher, penny-pinching, penurious, pinchfist, pinchgut,
   pinchpenny, save-all, scrooge, shabby, skinflint, sordid, stiff,
   tight, tightwad