noun
Refers to a person of strong moral integrity and courage, often in a political or historical context. Can carry a slightly literary or formal tone.
彼は国のために戦った烈士として知られている。
He is known as a patriot who fought for his country.
歴史に名を残す烈士たちの生き方に感銘
I was impressed by the lives of the heroes who left their names in history.
From Chinese 烈士 (lièshì), meaning a person of high moral principle and courage, often one who dies for a cause. The Japanese reading is the on'yomi of the characters.