also: さいぜん
taru-adjective, adverb taking the 'to' particle
Literary or formal word used to describe a clear, sharp distinction or separation. Often appears as 截然と or 截然たる.
両者の意見は截然と分かれた。
The opinions of the two sides were sharply divided.
彼の態度は截然としている。
His attitude is clear-cut.
The kanji 截 means 'cut' or 'sever', and 然 is a suffix forming adjectives/adverbs. The word likely originated from classical Chinese, meaning 'cuttingly clear' or 'sharply distinct'.