Meaning of “intervene” - Learner’s Dictionary

intervene

verb [ I ] uk us /ˌɪntəˈviːn/
BECOME INVOLVED

to become involved in a situation in order to try to stop a fight, argument, problem, etc:

Government officials refused to intervene in the recent disputes.
[ + to do sth ] The forces intervened to stop the attack.
INTERRUPT

to interrupt someone who is talking:

"Mr Lawrence," the judge intervened, "please be silent."
PREVENT

If something intervenes, it stops something or prevents it from happening:

She was going to marry Barratt but tragedy intervened.

(Definition of “intervene” from the Cambridge Learner’s Dictionary © Cambridge University Press)