disunite \dis`unite"\, v. t. imp.  p. p. disunited; p. pr.
    vb. n. disuniting.
   1. to destroy the union of; to divide; to part; to sever; to
      disjoin; to sunder; to separate; as, to disunite particles
      of matter.
      1913 webster

   2. to alienate in spirit; to break the concord of.
      1913 webster

            go on both in hand, o nations, never be disunited,
            be the praise . . . of all posterity --milton.
      1913 webster
see also:
disunited disuniting