intervene

IPA: ɪntɝvˈin

(intransitive) To become involved in a situation, so as to alter or prevent an action.
(intransitive) To occur, fall, or come between, points of time, or events.
(intransitive) To occur or act as an obstacle or delay.
(transitive, intransitive) To say (something) in the middle of a conversation or discussion between other people, or to respond to a situation involving other people.
(transitive, intransitive) To come between, or to be between, persons or things.
(law) 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.

Examples of "intervene" in Sentences

The teacher had to intervene when the students started arguing in the classroom
The police officer had to intervene to break up the fight on the street
The doctor decided to intervene and perform surgery to save the patient's life
I was about to intervene in the argument, but then realized they could handle it on their own
The government decided to intervene in the market to stabilize prices