The Collaborative International Dictionary of English v.0.48:

Disconnection \Dis`con*nec"tion\, n.
   The act of disconnecting, or state of being disconnected;
   separation; want of union.
   [1913 Webster]

         Nothing was therefore to be left in all the subordinate
         members but weakness, disconnection, and confusion.
                                                  --Burke.
   [1913 Webster]

WordNet (r) 3.0 (2006):

disconnection
    n 1: state of being disconnected [syn: disjunction,
         disjuncture, disconnection, disconnectedness] [ant:
         connectedness, connection, link]
    2: an unbridgeable disparity (as from a failure of
       understanding); "he felt a gulf between himself and his
       former friends"; "there is a vast disconnect between public
       opinion and federal policy" [syn: gulf, disconnect,
       disconnection]
    3: the act of breaking a connection [syn: disconnection,
       disjunction]

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "disconnection":
   abstraction, alienation, alternating personality, broken thread,
   brokenness, depersonalization, detachment, disarticulation,
   disassociation, disconnectedness, discontinuance, discontinuation,
   discontinuity, discontinuousness, discreteness, disengagement,
   disjointing, disjunction, disjuncture, dislocation, dissociation,
   dissociation of personality, disunion, division, divorce,
   divorcement, double personality, dual personality,
   emotional dissociation, episode, fitfulness, immateriality,
   impertinence, inapplicability, inappositeness, incoherence,
   incompleteness, inconnection, inconsequence, independence,
   intermittence, irregularity, irrelation, irrelevance, isolation,
   luxation, mental dissociation, multiple personality, non sequitur,
   noncontinuance, nonlinearity, nonseriality, nonuniformity,
   paranoia, paranoid personality, parenthesis, parting, partition,
   personality disorganization, removal, schizoid personality,
   schizoidism, schizophrenia, schizothymia, segmentation,
   separateness, separation, separatism, split personality,
   subdivision, subtraction, unconnectedness, unrelatedness,
   withdrawal, zoning