交戦|こうせんkousen[0]heiban (flat)

1. noun, suru verb, intransitive verbwar; battle; hostilities
   わが軍ぐんは敵てきと交戦こうせんした。↗

   Our troops engaged with the enemy.

• Synonym戦闘せんとうNeutralRefers to concrete combat operations, with the focus on the fighting itself, while 「交戦」 stresses that two sides are in a state of engagement.
• Synonym合戦かっせんWrittenA clash of two armies, with a historical flavor; also for modern and metaphorical showdowns like 「歌合戦」. 「交戦」 is the term for modern military hostilities, as in 「交戦国」.
• Synonym戦争せんそうNeutralWar between nations, on a large scale, viewing the whole state of war; also used metaphorically for fierce competition.
• Synonym一戦いっせんWrittenWritten style, for one battle or one match; it counts a single bout and says nothing about whether the sides are in a state of engagement.
• Synonym戦いくさNeutralA native word for war or battle, and also for troops; common in speech too, as in 「戦に出る」. 「交戦」 is a Sino-Japanese word, found mostly in news and official documents.
• Synonym戦うたたかうNeutralA verb covering fighting in battle, striving, and competing in matches; the broadest of these words and more colloquial than 「交戦」.
• Synonym戦いたたかいNeutralA noun for battle or struggle, military or not, also metaphorical struggles such as against illness. 「交戦」 covers only two sides fighting each other.
• SynonymコンバットCasualA loanword for combat, military or otherwise, with limited uses; everyday speech prefers 「戦闘」 or 「バトル」. 「交戦」 is the formal term, mainly in news reports.
• SynonymバトルCasualA loanword for a battle or matchup, colloquial, common in games, variety shows and contests. 「交戦」 is the formal term, seen mainly in news reports.
• Related戦いくさNeutralA native word for war or battle, and also for troops; common in speech too, as in 「戦に出る」. 「交戦」 is a Sino-Japanese word, found mostly in news and official documents.
• Related衝突しょうとつNeutralA collision, but also a clash of opinions or an armed clash, as in 「武力衝突」. 「交戦」 refers only to the two sides actually fighting each other.
• Related喧嘩けんかCasualColloquial, for quarrels and brawls between individuals or small groups; not a military engagement.
• Related抗争こうそうNeutralRivalry or struggle between groups, as in 「派閥抗争」; force is not necessarily involved.
• Related争うあらそうNeutralA verb for contending, competing or arguing, with broad uses beyond armed conflict. 「交戦」 refers specifically to combat.
• Related闘争とうそうWrittenWritten style, for struggle or fighting, armed struggle included; common for labor or political struggles. 「交戦」 refers specifically to two sides in combat.
• Related争闘そうとうWrittenRefers to strife or fighting; rare even in written prose. A general term for conflict, not limited to armed exchanges between military forces.
• RelatedやりあうCasualColloquial, for people arguing, quarrelling or competing with each other, mostly between individuals. 「交戦」 is a military term for two sides in combat.
• Antonym休戦きゅうせんNeutralAn agreed temporary halt to fighting, with the state of war continuing; the opposite of 「交戦」 in whether combat is under way.
• Antonym停戦ていせんFormalFormal, for an agreed stop to fighting, as in 「停戦協定」; the opposite of 「交戦」 in whether combat is under way.

Use 「交戦」 for armed forces exchanging fire or being in a state of war, as in 「交戦状態」 or 「交戦国」; it is the formal term, typical of news reports. For the fighting itself say 「戦闘」, for a whole war 「戦争」, and colloquially for a matchup 「バトル」. The opposite is 「停戦」. Several others reach beyond warfare: 「喧嘩」 and 「やり合う」 are personal quarrels, 「抗争」 group rivalry, and 「争う」「戦う」 also cover competition.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 互たがいに戦たたかうこと。