intervene
Definitions
To come between disputing people, groups, or things to prevent or alter a result or course of events.
To occur or be situated between two events, periods of time, or objects.
To interfere with an outcome or process, typically to improve a situation.
Examples
The teacher had to intervene when the two students began to argue in the hallway.
The government decided to intervene in the failing economy to prevent a total collapse.
Synonyms
mediate arbitrate intercede interpose interfere intrude step in