gatekeeper

名词 gatekeeper:

1. someone who controls access to something
2. someone who guards an entrance
   同义词：doorkeeper, doorman, door guard, hall porter, porter, ostiary

gate.keep.er

n.（名词）
One that is in charge of passage through a gate.
看门人：掌管通过一大门的人
One who monitors or oversees the actions of others.
一个监视或监督别人的举动的人