Refers to prioritizing one's own benefit, often with a negative connotation. Antonym: 利他 (altruism).
Antonyms: 利他
His actions are driven by self-interested motives.
If you act out of self-interest, you will lose the trust of those around you.
He always pursues his own self-interest and never thinks of others.
The decision was criticized as an action based on self-interest.
altruism
利口 (clever) and 利己 (selfish, self-interested) look almost identical in kanji but have unrelated meanings, so learners often mix them up.
From 利 (profit, benefit) and 己 (self). The compound directly conveys the idea of benefiting oneself.