Meaning of intervene

in•ter•vene

1. to come between disputing people, groups, etc.; intercede; mediate.
2. to occur or be between two things.
3. to occur or happen between other events or periods: Nothing important intervened between the meetings.
4. (of things) to occur incidentally so as to modify or hinder: We enjoyed the picnic until a thunderstorm intervened.
5. to interfere with force or a threat of force: to intervene in the affairs of another country.
6. to interpose and become a party to a suit pending between other parties.