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.
人口が急速に増えている。
The population is increasing rapidly.
技術は急速に進歩している。
Technology is advancing rapidly.
少子化の影響で、地方の人口が急速に減少している。
Due to the declining birthrate, the population in rural areas is decreasing rapidly.
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).