Sure
Sure adjective - Having or showing a mind free from doubt.
Usage example: are you absolutely sure that she said she was coming today?
Uncertain is an antonym for sure in topics: certain, unsure, inevitable, self-confident, physically stable.
Nearby Word: surely
Uncertain
Uncertain adjective - Likely to change frequently, suddenly, or unexpectedly.
Usage example: the stifling heat would occasionally be relieved by an uncertain breeze
Nearby Words: uncertainty, uncertainly
Both words in one sentence
- In the final episode Vicious dies for sure, but whether Spike survives or not is left uncertain.
Source: Only I Can Kill Him - Before all of this, I was always uncertain of everything and I guess I still am in a lot of ways, but at least this much I'm sure of.
- It's uncertain if Bruce and Alfred died at the very end or not, but it's done to make sure no one goes after the other masked heroes connected to him.
Source: Reality Ensues / Video Games
Cite this Source
Uncertain and Sure. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/sure/uncertain
Sure & Uncertain. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/sure/uncertain>.
Uncertain or Sure. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/sure/uncertain.
Google Ngram Viewer shows how "sure" and "uncertain" have occurred on timeline