蕩

It is a phono-semantic compound, composed of:

艸 (“grass, plants”) as the semantic element;

湯 (tang, “boiling, hot water”) as the phonetic element.

The original sense is linked to overflowing water, which later developed figuratively into “overflowing behavior” (dissipation, indulgence) and “to wash away, to sweep clean.”

蕩 carries both the concrete sense of washing away, sweeping clean and the figurative sense of indulgence, dissipation, making it a character with both physical and moral connotations in East Asian vocabulary.

In modern Korean, 탕 (蕩) appears in compounds with both negative and neutral senses:

방탕 (放蕩) – dissipation, profligacy

소탕 (掃蕩) – sweeping away, suppression, eradication

진탕 (盡蕩) – complete ruin, utter dissipation

탕진 (蕩盡) – squandering, waste

탕평 (蕩平) – sweeping equality, fair balance (used in politics)