The Collaborative International Dictionary of English v.0.48:

Disaccord \Dis`ac*cord"\, v. i. [Cf. F. d['e]saccorder to cause
   discord.]
   To refuse to assent. [Obs.] --Spenser.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Disaccord \Dis`ac*cord"\, n.
   Disagreement. --Pop. Sci. Monthly.
   [1913 Webster]

WordNet (r) 3.0 (2006):

disaccord
    v 1: be different from one another [syn: disagree,
         disaccord, discord] [ant: agree, check,
         correspond, fit, gibe, jibe, match, tally]