Webster's Revised Unabridged Dictionary · 1913

Disunite

Disunite , transitive verb

1.
To destroy the union of; to divide; to part; to sever; to disjoin; to sunder; to separate; as, to disunite particles of matter.
2.
To alienate in spirit; to break the concord of.
Go on both in hand, O nations, never be disunited, be the praise... of all posterity! — Milton

Disunite , intransitive verb

To part; to fall asunder; to become separated.
The joints of the body politic do separate and disunite. — South