1. Liquid
2. Unstable
3. Changeable
4. Pliable
5. Viscous
6. Runny
7. Slippery
8. Amorphous
9. Unsettled
10. Malleable
11. Supple
12. Variable
13. Volatile
14. Sloshy
15. Flowing
16. Mobile
17. Unfixed
18. Agile
19. Streamlined
20. Flickering
21. Unstable
22. Flexible
23. Unpredictable
24. Unconstant
25. Unceasing
26. Uncontrolled
27. Unchecked
28. Unbridled
29. Unconstrained
30. Unbounded

When searching for alternative words for the term fluid, there are a variety of options to consider. Some of the best ideas include liquid, unstable, changeable, pliable, viscous, runny, slippery, amorphous, and unsettled. These synonyms can be used to provide a more diverse range of language when describing a fluid-like substance. Other words for fluid may include malleable, supple, variable, volatile, sloshy, flowing, mobile, unfixed, and agile. There are many synonyms for fluid, but these are some of the best ideas to consider when looking for a more descriptive way to talk about fluid-like materials.