1. Perilous
2. Risky
3. Uncertain
4. Precarious
5. Treacherous
6. Chancy
7. Unsafe
8. Unreliable
9. Unsound
10. Dubious
11. Unstable
12. Unpredictable
13. Menacing
14. Unfavorable
15. Unsuitable
16. Unwholesome
17. Detrimental
18. Injurious
19. Deleterious
20. Parlous
21. Volatile
22. Unfortunate
23. Unhealthy
24. Unfavourable
25. Opprobrious
26. Disastrous
27. Periculous
28. Problematic
29. Unpromising
30. Disadvantageous

When looking for the best ideas for synonyms for the word «hazardous», it is important to consider the context in which the word is being used. For example, if the word is being used to describe a dangerous situation, words like perilous, risky, and treacherous may be more appropriate. On the other hand, if the word is being used to describe a situation that is uncertain or unreliable, words like chancy, dubious, and unstable may be more suitable. Whatever the context, there are plenty of other words for hazardous that can be used to convey the desired meaning. Some of the best ideas for synonyms for hazardous include perilous, risky, uncertain, precarious, treacherous, chancy, unsafe, unreliable, unsound, dubious, unstable, unpredictable, menacing, unfavorable, unsuitable, unwholesome, detrimental, injurious, deleterious, parlous, volatile, unfortunate, unhealthy, unfavourable, opprobrious, disastrous, periculous, problematic, unpromising, and disadvantageous.