What does 宣戦 mean?
宣戦 is a Japanese noun meaning “declaration of war” in English. It is written as 宣戦 in kanji, せんせん in hiragana, and sensen in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
その国は隣国に対し宣戦を布告した。
The country declared war against its neighbor.