IPA: /ɪnˈtɜːrvɪnər/
KK: /ɪnˈtɜrvɪnər/
A person who takes part in a situation to help or prevent something from happening.
The intervener stepped in to resolve the conflict between the two parties.
Intervener → It is formed from "inter-" (meaning between) and "venire" (meaning to come). The word describes someone who comes in between to take action or intervene in a situation.
Think of someone 'coming in between' ('inter-') to help or take action — that's what an intervener does.