Killed In Action, Death In Battle, KIA
noun, verbal noun
When a person dies in a war they're considered to have been killed in action. There are lots of memorials around the world for people who died this way.
せんぼつ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
たくさんの戦没した兵士たちがここに埋められています。
Many soldiers who were killed in action are buried here.