戦
This Chinese character means war, battle, fight.
You can watch how to write this. - (「戦」の書き順（筆順）動画 - 漢字書き順辞典)
There are 2 main ways to read this, "せん" or "たたかう (戦う)".
When this is combined with other Chinese characters, this is often read as "せん".
For example, "戦争 (せんそう)" means war.
"戦闘 (せんとう)" means battle.
And "戦国時代 (せんごくじだい)" means Sengoku period.
"時代 (じだい)" means period.
Many Japanese people love Sengoku period.
Why? They are even now so warlike?
No, because many Japanese people like to watch Taiga drama.
Taiga drama is a popular TV series of NHK which is national broadcasting organization of Japan.
And many Taiga dramas were stories of Sengoku period heroes.
There are many heroes and interesting stories of Sengoku period.
I also like it.
By Higashi-Mikawa Kyōjindō Shujin (東三河狂人堂主人)