moderator

名词 moderator:

1. any substance used to slow down neutrons in nuclear reactors
2. in the Presbyterian church, the officer who presides over a synod or general assembly
3. someone who presides over a forum or debate
4. someone who mediates disputes and attempts to avoid violence

mod.er.a.tor

n.（名词）
One that moderates, as:
仲裁的人
One that arbitrates or mediates.
公断人或调解人
One who presides over a meeting, forum, or debate.
主持人：主持会议，论坛或讨论会的人
The officer who presides over a synod or general assembly of the Presbyterian Church.
主持官员：主持基督教长老会的会议或大会的官员
Physics A substance, such as water or graphite, that is used in a nuclear reactor to decrease the speed of fast neutrons and increase the likelihood of fission.
【物理学】 慢化剂：一种物质，如水或石墨在核反应堆中用来减缓中子运动速度和提高裂变可能性的物质