Origin

The character combines the nose (自) sitting above the heart (心) to represent breath and respiration—the idea of air passing through the nose and affecting the heart's functioning. Since breath is essential to life and tied to one's inner state, the character expanded to mean related concepts: a son (seen as an extension of oneself), rest (when breathing slows), interest accruing (growing quietly like breath), and the ending of something (when breath stops). The stacking of these two body-related components creates a unified image of the vital, continuous process of breathing.

AI-generated (claude-haiku-4-5), not yet reviewed. Formation type (automated guess): Compound ideographic (combined meanings).