The Collaborative International Dictionary of English v.0.48:

Disinterest \Dis*in"ter*est\, p. a.
   Disinterested. [Obs.]
   [1913 Webster]

         The measures they shall walk by shall be disinterest
         and even.                                --Jer. Taylor.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Disinterest \Dis*in"ter*est\, n.
   1. What is contrary to interest or advantage; disadvantage.
      [Obs.] --Glanvill.
      [1913 Webster]

   2. Indifference to profit; want of regard to private
      advantage; disinterestedness. [Obs.] --Johnson.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Disinterest \Dis*in"ter*est\, v. t.
   To divest of interest or interested motives. [Obs.]
   --Feltham.
   [1913 Webster]

WordNet (r) 3.0 (2006):

disinterest
    n 1: tolerance attributable to a lack of involvement [syn:
         disinterest, neutrality]