Arbitrary
Arbitrary adjective - Having or showing a tendency to force one's will on others without any regard to fairness or necessity.
Usage example: an arbitrary piano teacher who makes all her students do the same exercises over and over again
Unreasonable is a synonym for arbitrary in whimsical topic. In some cases you can use "Unreasonable" instead an adjective "Arbitrary", when it comes to topics like random, unjustified, unmotivated.
Unreasonable
Unreasonable adjective - Having no basis in reason or fact.
Arbitrary is a synonym for unreasonable in extravagant topic. You can use "Arbitrary" instead an adjective "Unreasonable", if it concerns topics such as unjustified, not logical or sensible.
Mutual synonyms
Both words in one sentence
- Instead of being a kind loving Matriarch, the mother is strict, arbitrary, unreasonable, and has a volcanic temper.
Cite this Source
Unreasonable and Arbitrary. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/arbitrary/unreasonable
Arbitrary & Unreasonable. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/arbitrary/unreasonable>.
Unreasonable or Arbitrary. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/arbitrary/unreasonable.
Google Ngram Viewer shows how "arbitrary" and "unreasonable" have occurred on timeline