In Chinese culture, displaying proper respect for ancestors, history, and formal authority is paramount. 肃穆 (sùmù) is the word that perfectly captures the ideal atmosphere for such occasions. It is the expected mood during events like the Qingming Festival (清明节, Tomb-Sweeping Day), when families visit and clean ancestral graves, or when visiting significant historical sites like the Nanjing Massacre Memorial Hall. A helpful comparison for a Western learner is the atmosphere at the Tomb of the Unknown Soldier or the Lincoln Memorial in Washington, D.C. Visitors instinctively lower their voices and move slowly, not just because it's quiet, but out of a shared, unspoken reverence for the history and sacrifice the place represents. This is a very 肃穆 (sùmù) environment. While a Western funeral might include moments of laughter while sharing fond memories, a traditional Chinese event described as 肃穆 (sùmù) would lean much more heavily on quiet, collective remembrance and deep, formal respect. The focus is less on individual expression of grief and more on the shared gravity of the moment.
肃穆 (sùmù) is a formal, often literary word. You are more likely to encounter it in writing, news reports, documentaries, or formal speeches than in casual, everyday conversation.
It is crucial to remember that 肃穆 (sùmù) describes a temporary state or atmosphere; you would almost never use it to describe a person's permanent personality.