noun
selflessness; selfless devotion to others
A somewhat formal or literary term emphasizing altruism and putting others before oneself. Often used in ethical or philosophical contexts.
彼の行動は忘己利他の精神に基づいている。
His actions are based on the spirit of selfless devotion to others.
忘己利他を実践することは容易ではない。
It is not easy to practice selflessness.
利他 means 'altruism' or 'benefiting others' and is more common in everyday and academic contexts. 忘己利他 adds the nuance of forgetting oneself, making it a stronger, more self-sacrificial concept.
自己犠牲 means 'self-sacrifice' and focuses on giving up one's own interests, often with a connotation of loss. 忘己利他 emphasizes devotion to others without necessarily implying loss.
A yojijukugo (four-character compound) composed of 忘 (forget), 己 (self), 利 (benefit), and 他 (others). The exact historical origin is uncertain, but it reflects a Buddhist-influenced ideal of selfless compassion.