Irrational and Reasonable

Irrational

Irrational adjective - Not using or following good reasoning.
Usage example: it's irrational to think that you can continue to consume an excess of calories and not gain weight

Reasonable is an antonym for irrational in illogical topic.

Nearby Words: irrationality, irrationally

Reasonable

Reasonable adjective - According to the rules of logic.
Usage example: his answer is perfectly reasonable

Irrational is an antonym for reasonable in topics: sensible, moderate, intelligent.

Both words in one sentence

  • For example, a villain who robs banks to pay for his sick daughter's medical treatment might be reasonable, but it becomes completely irrational when the daughter isn't even sick anymore.
  • Reasonable Authority Figure: Although most of the adults have their irrational moments, they generally fall into this category.
  • The Kirk As a result he can either side with the irrational and uncontrollable Adam or the more buttoned-down and reasonable Anders at any given moment.
    Source: The Kirk
Cite this Source
Reasonable and Irrational. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/irrational/reasonable
Irrational & Reasonable. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/irrational/reasonable>.
Reasonable or Irrational. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/irrational/reasonable.
Google Ngram Viewer shows how "irrational" and "reasonable" have occurred on timeline