a state or law official

person who arbitrates

(to be) the presenter of a stage, TV or radio entertainment who introduces the performers, speakers etc

formal host

a person employed in diplomacy for her or his country e.g. an ambassador

politician, consul

a public official with authority to hear and decide cases in a law court

person who arbitrates

refer; reference

judge

an expert in tactics

politician, consul

a person who controls games and competitions

person who settles dispute