definition of
rapid

[1] #1 rapid s. done or occurring in a brief period of time; "a rapid rise through the ranks". wn

[2] #2 rapid n. a part of a river where the current is very fast. wn

[3] #3 rapid s. [speedy] characterized by speed; moving with or capable of moving with high speed; "a rapid movement"; "a speedy car"; "a speedy errand boy". wn