What is the meaning of Intervene?

To become involved in a situation, so as to alter or prevent an action.

To occur, fall, or come between, points of time, or events.

To occur or act as an obstacle or delay.

To say (something) in the middle of a conversation or discussion between other people, or to respond to a situation involving other people.

To come between, or to be between, persons or things.

In a suit to which one has not been made a party, to put forward a defense of one's interest in the subject matter.

Source: wiktionary.org