The Collaborative International Dictionary of English v.0.48:

Disjoin \Dis*join"\ (d[i^]s*join"), v. t. [imp. & p. p.
   Disjoined (d[i^]s*joind"); p. pr. & vb. n. Disjoining.]
   [OF. desjoindre, F. disjoindre, d['e]joindre, fr. L.
   disjungere; dis- + jungere to join. See Join, and cf.
   Disjoint, Disjunct.]
   To part; to disunite; to separate; to sunder.
   [1913 Webster]

         That marriage, therefore, God himself disjoins.
                                                  --Milton.
   [1913 Webster]

         Never let us lay down our arms against France, till we
         have utterly disjoined her from the Spanish monarchy.
                                                  --Addison.
   [1913 Webster]

         Windmill Street consisted of disjoined houses.
                                                  --Pennant.

   Syn: To disunite; separate; detach; sever; dissever; sunder;
        disconnect.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Disjoin \Dis*join"\, v. i.
   To become separated; to part.
   [1913 Webster]

WordNet (r) 3.0 (2006):

disjoin
    v 1: make disjoint, separated, or disconnected; undo the joining
         of [syn: disjoin, disjoint] [ant: bring together,
         join]
    2: become separated, disconnected or disjoint [syn: disjoin,
       disjoint] [ant: conjoin, join]