Wordnet 3.0
NOUN (1)
1. 
 a crusty irascible cantankerous old person full of stubborn ideas; 
The Collaborative International Dictionary of English v.0.48:
Curmudgeon \Cur*mudg"eon\ (k?r-m?j"?n), n. [OE. cornmudgin,
   where -mudgin is prob. from OF. muchier, mucier, F. musser to
   hide; of uncertain origin; cf. OE. muchares skulking thieves,
   E. miche, micher.]
   An avaricious, grasping fellow; a miser; a niggard; a churl.
   [1913 Webster]
         A gray-headed curmudgeon of a negro.     --W. Irving.
   [1913 Webster]
WordNet (r) 3.0 (2006):
curmudgeon
    n 1: a crusty irascible cantankerous old person full of stubborn
         ideas