1. Quickly
2. Speedily
3. Swiftly
4. Fast
5. Rapid
6. At once
7. Instantly
8. Hurriedly
9. Directly
10. Immediately
11. Rapidly
12. Quick
13. Expeditiously
14. Haste
15. Promptly
16. Post Haste
17. In a jiffy
18. In the blink of an eye
19. On the double
20. Like a shot
21. Like lightning
22. Like a flash
23. In no time
24. In a trice
25. In a moment
26. In a twinkling
27. In a second
28. In a New York minute
29. In a flash
30. In a trice

When you need to find another word for rapidly, the best ideas are to use synonyms such as quickly, speedily, swiftly, fast, and rapid. These words all mean the same thing and can be used interchangeably when you need to describe something that is happening in a short amount of time. Synonyms for rapidly can also be used to add variety to your writing or to make a piece of writing more interesting. Using synonyms for rapidly can help you to communicate your ideas more effectively and make your writing more impactful.