1.
battle, combat
A military battle or armed conflict. Often used in historical contexts, especially for premodern Japanese warfare.
関ヶ原の合戦は有名だ。
The Battle of Sekigahara is famous.
両軍は激しい合戦を繰り広げた。
Both armies engaged in fierce battle.
歴史の授業で戦国時代の合戦について学んだ。
We studied battles from the Sengoku period in history class.
2.
contest, fierce competition
A heated contest or rivalry, used figuratively for non-military competitions.
雪合戦をして遊んだ。
We played a snowball fight.
商店街では安売り合戦が始まった。
A price-cutting war has started in the shopping district.
選挙前になると、各党の宣伝合戦が激しくなる。
Before elections, the publicity battles between parties intensify.
USAGE:
Sense 1 is used primarily in historical contexts, especially premodern Japanese warfare. In modern Japanese, 戦闘 or 戦争 are more common for contemporary conflicts. Sense 2 is common in compounds like 雪合戦 (snowball fight) and 安売り合戦 (price war).
PRONUNCIATION:
When used as a standalone word, the reading is かっせん. In compounds, it often becomes がっせん (voiced): 雪合戦, 宣伝合戦.
COMMON COLLOCATIONS:
- 合戦を繰り広げる: to wage battle
- 雪合戦: snowball fight
- 安売り合戦: price war
- 宣伝合戦: publicity battle