n.
1.any substance used to slow down neutrons in nuclear reactors
2.in the Presdyterian 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
Idiom of the Day
get close to (something)
to be almost as good as something, to almost reach or arrive at a goal
The charity is getting close to the final amount of money that they expect to collect.