1. Against the flow
2. Against the current
3. Adverse
4. Antithetical
5. Backward
6. Contrarious
7. Counter
8. Contrary
9. Inverse
10. Opposed
11. Opposite
12. Reverse
13. Uphill
14. Ascendant
15. Ascending
16. Backward-facing
17. Upbound
18. Upward
19. Upward-facing
20. Upwardly
21. Adverse
22. Antipodal
23. Antithetic
24. Cross
25. Cross-current
26. Crosswise
27. Inimical
28. Retrograde
29. Unfavorable
30. Unfriendly

Finding the right words to describe something can be hard, especially when it comes to complex topics. If you are looking for synonyms for the word “upstream,” you’ve come to the right place. Here are the best ideas and other words for “upstream”: against the flow, against the current, adverse, antithetical, backward, contrarious, counter, contrary, inverse, opposed, opposite, reverse, uphill, ascendent, ascending, backward-facing, upbound, upward, upward-facing, upwardly, adverse, antipodal, antithetic, cross, cross-current, crosswise, inimical, retrograde, unfavorable, and unfriendly. With this list of synonyms, you will never be at a loss for words when it comes to describing something that is moving upstream.