Antonyms for "rendering uncertain" could be words such as "clarify," "explain," or "confirm." These words suggest a process of making something clear, understandable, and definite. Other antonyms that come to mind include "resolving," "settling," or "determining". These words imply a process of bringing a situation to a conclusion or finding a solution. Additionally, "verifying," "validating," or "endorsing" could also serve as antonyms. These words suggest a process of checking or confirming the accuracy or authenticity of something, which would remove ambiguity and make it certain.Overall, antonyms for "rendering uncertain" focus on bringing clarity, resolution, and confidence to a situation.