Lieutenant Colonel
Navy Commander
noun
The middle help in the army or navy is the lieutenant colonel or the navy commander. I'm guessing these ranks are kind of in the middle or middle high end of the ranking scales?
ちゅうさ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
中佐は、日本への移住に反対することを決めた。
The lieutenant colonel decided against immigrating to Japan.