irrational
Translation
irrational, illogical, unreasonable
Examples
He has an irrational fear of spiders.
He has an irrational fear of spiders.
Her decision seemed completely irrational.
Her decision seemed completely irrational.
Grammar Patterns
an irrational ((noun)) an irrational fear He has an irrational fear of heights.
it is irrational ((to-inf)) it is irrational to do (sth.) It is irrational to spend all your money.
Similar Words
Synonyms: illogical, unreasonable, absurd; Antonyms: rational, logical, reasonable
Etymology
Prefix 'ir-' (a form of 'in-') meaning 'not' + 'rational'. So, literally 'not rational'.
Memory Tips
The prefix 'ir-' often means 'not', like in 'irregular' or 'irresponsible'. So, irrational = not rational.