利子
りし · rishi · JLPT N1 · noun
interest
利 — grain 禾 + knife 刂
Originally a pictograph showing a knife (刂) cutting grain (禾), depicting harvest. From the idea of a sharp blade reaping crops, it extended to mean 'sharp,' then 'benefit,' 'profit,' or 'advantage' — the gain that comes from a successful harvest.
子 — pictograph of a baby/child with arms out
子 began as a pictograph of a swaddled infant with a large head and outstretched arms, originally meaning 'baby' or 'child.' From there it broadened to 'son,' 'offspring,' and a respectful suffix for masters like 孔子 (Confucius). It also became one of the twelve earthly branches.