In a Nutshell: Think of
下跌 (xiàdiē) as the word you see in a news headline about the stock market. It's not for a person tripping on the sidewalk (that's
摔倒 - shuāidǎo). Instead, it describes a more abstract, often numerical, “fall” or “drop”—like prices, temperatures, or a company's popularity. It carries a neutral to slightly negative, formal tone, perfect for reports and objective descriptions.