RAPID

[adjective] - quick or suddenI was startled by a rapid movement to my left.His response to the accusation was rapid.There has been a rapid growth/rise/increase/expansion in the number of people who have home computers.The industry is currently undergoing rapid change.Since we began our campaign, we have made rapid strides (= advanced quickly).We were woken by the sound of rapid fire (= shooting).As a comedian, he's a master of rapid-fire jokes (= those coming quickly one after another).There are plans to build a new rapid transit system (= a system of fast moving trains) in the city.