溢

A phono-semantic compound composed of:

水 (氵) — semantic component meaning “water”;

益 — phonetic component indicating the sound (일 / yì). The character originally described water overflowing a container, which later expanded to abstract meanings like excess or abundance.
Semantic development: - water overflowing; - exceeding capacity; - abundance (emotion, energy, etc.).

일출 (溢出) — overflow; outflow

일류 (溢流) — overflow current; overflow

溢 is often used metaphorically in expressions like joy overflowing or energy overflowing. It conveys a stronger nuance than simple “full,” emphasizing excess beyond capacity.
Related characters: 満 — to be full 溢 — to overflow 流 — to flow