Certain
Certain adjective - Having been established and usually not subject to change.
Usage example: a certain percentage of the profits will go to charity
Unpredictable is an antonym for certain in topics: fixed, confident, undoubtable, referring to a specifically known amount.
Unpredictable
Unpredictable adjective - Likely to change frequently, suddenly, or unexpectedly.
Usage example: unpredictable spring weather that makes it really hard to know what to wear
Nearby Word: unpredictability
Both words in one sentence
-
This gets lampshaded when Anton decides that the only way to be certain that he isn't taking the option Zavulon wants him to take is to invent an entirely new and unpredictable one.
Source: Literature / Night Watch -
The hidden magnet in The Addams Family will pulse at certain timesnote when 2 balls are locked out of three for Showtime Multiball, during all multiball modes, and during Seance, flinging the ball in unpredictable directions, sometimes right into an outlane or a drain.
Source: Scrappy Mechanic - In such circumstances, a certain minimum amount of unforeseeable uncertainty is a given, and unexpected results are not unexpectednote And if we're talking human behavior, then there are those who would claim that it's really not that unpredictable.
Source: This Index Is Highly Improbable
Cite this Source
Unpredictable and Certain. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/certain/unpredictable
Certain & Unpredictable. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/certain/unpredictable>.
Unpredictable or Certain. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/certain/unpredictable.
Google Ngram Viewer shows how "certain" and "unpredictable" have occurred on timeline