not based on, or not using, clear logical thought synonym unreasonable opposite rational不合逻辑的;没有道理的 Extra ExamplesThere was nothing inherently irrational in such a decision. 从根本上看,这样的决定没什么不合理的地方。 What is the reason for this seemingly irrational behaviour? 这种看似不理智的行为是出于什么原因?
Oxford Collocations Dictionaryverbs- appear
- be
- seem
- …
- completely
- quite
- totally
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Word Originlate Middle English: from Latin irrationalis, from in- ‘not’ + rationalis (from ratio(n-) ‘reckoning, reason’, from rat- ‘reckoned’, from the verb reri).