迅即 is an adverb meaning 'immediately' or 'at once', emphasizing speed and no delay. The first character 迅 (xùn) means 'swift' or 'rapid', often seen in words like 迅速 (xùnsù, 'quickly') and 迅雷 (xùnléi, 'sudden thunder'). The second character 即 (jí) means 'right away' or 'at once', as in 立即 (lìjí, 'immediately') and 即刻 (jíkè, 'this very moment'). Together, 迅即 forms a compact, formal compound that conveys urgency and instant action.

This word is commonly used in written Chinese—especially in news reports, official announcements, and formal narratives—to describe rapid responses to events (e.g., emergency reactions, policy implementations, or natural phenomena). It is more literary and concise than everyday alternatives like 马上 (mǎshàng) or 立刻 (lìkè), and rarely appears in casual speech. While grammatically similar to other time adverbs, 迅即 typically precedes the verb and does not take aspect particles like 了 or 过.