1.
rapidly; quickly; at a fast pace
Describes something happening or changing at a noticeably fast rate. Often used in news and academic writing about trends and developments.
Commonly appears in news articles and formal writing about societal changes, economic trends, and technological developments. Common collocations include 急速に発展する (to develop rapidly), 急速に広まる (to spread rapidly), and 急速に変化する (to change rapidly). The base form 急速 can also function as a な-adjective: 急速な変化 (rapid change).