At (full) speed, a mile a minute, and abruptly are all synonyms for rapidly. Slowly and gradually are antonyms of rapidly. And here are 49 another word for rapidly.
A mile a minute, abruptly, at (full) speed, at a gallop, at a rate of knots, at full tilt, at the double, at the speed of light, at warp speed, before one can say knife, briskly, double quick, expeditiously, fast and furious, fast, hastily, hell for leather, hotfoot, hurriedly, in a flash, in a hurry, in a rush, in haste, lickety-split, like (greased) lightning, like a bat out of hell, like a bomb, like a madman/madwoman, like a scalded cat, like a shot, like a streak, like billy-o, like blazes, like crazy, like mad, like nobody's business, like the clappers, like the deuce, like the wind, p.d.q. (pretty damn quick), post-haste, precipitately, promptly, pronto, quickly, speedily, swiftly, and apace are all synonyms for rapidly.
Rapidly synonym page has a variety of synonyms that differ in length. 1 synonym with 4, 6, and 18 letters and 8 synonyms with 7 letters. 5 synonyms with 8 letters and 6 synonyms with 9, and 11 letters.
3 synonyms with 10, 12, and 14 letters and 2 synonyms with 13, 15, 17, 19, and 20 letters. For a total of 47 another word for rapidly.
Technology is advancing rapidly these days.
She is improving rapidly in class.
The weather changed rapidly overnight.
His heart was beating rapidly.