intervene

To involve oneself in a situation so as to alter or hinder an action or development.

To interfere, usually through force or threat of force, in the affairs of another nation.

To enter into a lawsuit as a third party to assert a claim against one or both of the existing parties.

To come, appear, or lie between two things.

To come or occur between two periods or points of time.

To occur as an extraneous or unplanned circumstance.

A coming together; a meeting.

To come between; fall or happen between things, persons, periods, or events; be intermediate, or appear or happen intermediately.

To come between in act; act intermediately or mediatorially; interfere or interpose, as between persons, parties, or states.