Noun
がいこうかん
あの外交官は、どうしてけっこんして身を固めないんだろう。
I wonder why that diplomat doesn't get married and settle down.
私のおじは外交官で、世界に数台しかないギターを他の国の外交官からプレゼントされました。
My uncle is a diplomat and a diplomat from another country gave him a rare guitar, which is one of only a few that exist in the world.
私は外交官で、どうしても今日日本に飛ばなければいけないんです。空席待ちをさせてもらえますか？
I’m a diplomat and I really need to fly to Japan today, so could you put me on the waiting list?
Someone from the outside who comes in to mix with the government is a diplomat. Really, that's what diplomats do, right? They come from the outside (country). They mix with the government, and they do what they're there to do!
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.