Certain
Certain adjective - Impossible to avoid or evade.
Usage example: as he got older, the athlete began to feel the certain effects of the aging process on his body
Questionable is an antonym for certain in topics: known, fixed, confident, undoubtable, referring to a specifically known amount.
Questionable
Questionable adjective - Giving good reason for being doubted, questioned, or challenged.
Usage example: the runner's unexpected first-place finish is questionable, so a drug test has been ordered
Both words in one sentence
- The ending of HalfLife presents the player with a choice of entering employment of a mysterious being of questionable intentions (and ending up in stasis for 20 years) or certain death.
Source: Questionable Consent - Going so far as to threaten someone with a certain Dimensional of questionable activities and taking the same person and imprisoning them in the Zone of Silence.
- Although between his status as The Ghost and the coach's...questionable mental state, it's not 100% certain that Greenburg really exists.
Source: Butt Monkey / Live-Action TV
Cite this Source
Questionable and Certain. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/certain/questionable
Certain & Questionable. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/certain/questionable>.
Questionable or Certain. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/certain/questionable.
Google Ngram Viewer shows how "certain" and "questionable" have occurred on timeline