消沉
xiāo chén · HSK 7
to sink into despondency; (of morale, willpower etc) to diminish; to plummet
🥀 消 dissipate/vanish + 沉 sink = energy fades and sinks down into low spirits
消 means to dissipate or use up; 沉 means to sink. Together the spirit gets used up and sinks low — depressed, downcast, in a bad mood.
消 — water 氵 + 肖 (phonetic)
消 is a semantic-phonetic compound: the water radical 氵 indicates the meaning, while 肖 (xiào) supplies the sound. It originally described water dwindling or melting away, and from there extended to the modern senses of vanishing, dissolving, and dispelling.
沉 — water 氵 + 冘 (phonetic, sinking figure)
Originally written 沈, this character combines the water radical 氵 with 冘, depicting a person sinking. It pictured an object or person submerged in water, giving the core meaning 'to sink.' From there it extended metaphorically to 'deep,' 'heavy,' and 'submerged in thought,' as in 沉默 (silent) or 沉重 (heavy).