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 two students started arguing in the classroom
The police officer decided to intervene and break up the fight that had broken out on the street
The therapist knew it was time to intervene when her patient's mental health began to deteriorate
The referee had to intervene to prevent a player from breaking the rules during the game
The government decided to intervene by providing aid to the poverty-stricken community