Certain
Certain adjective - Having been established and usually not subject to change.
Usage example: a certain percentage of the profits will go to charity
Unstable
Unstable adjective - Likely to change frequently, suddenly, or unexpectedly.
Usage example: financial investors don't like an unstable economy
Nearby Word: unstably
Both words in one sentence
- Unstable Equilibrium: A player who gets far enough ahead is almost certain to win the game.
Source: Tabletop Game / Backgammon -
Unfortunately, after a certain number of copies they get a little unstable and less like herself.
Source: Self-Duplication -
In some cases, an unstable internet connection will cause certain browsers to think they're still loading when the connection is already broken.
Source: Loads and Loads of Loading
Cite this Source
Unstable and Certain. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/certain/unstable
Certain & Unstable. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/certain/unstable>.
Unstable or Certain. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/certain/unstable.
Google Ngram Viewer shows how "certain" and "unstable" have occurred on timeline