The Collaborative International Dictionary of English v.0.48:

Disassociate \Dis`as*so"ci*ate\, v. t. [imp. & p. p.
   Disassociated; p. pr. & vb. n. Disassociating.]
   To disconnect from things associated; to disunite; to
   dissociate. --Florio.
   [1913 Webster]

WordNet (r) 3.0 (2006):

disassociate
    v 1: part; cease or break association with; "She disassociated
         herself from the organization when she found out the
         identity of the president" [syn: disassociate,
         dissociate, divorce, disunite, disjoint]