irrational
- 01 B2 Upper Intermediate
adj.not based on reason or clear thinking.
adj.lacking logical justification or sound reasoning; often used to describe emotions, fears, or decisions.
Simple“She had an irrational fear of spiders, even though she knew they were harmless.”
In context“The market's reaction was entirely irrational, driven more by panic and hearsay than by any concrete changes in economic data.”
SynonymsAntonyms - 02 C1 Advanced
adj.describes a number that cannot be written as a simple fraction.
adj.relating to a real number that cannot be expressed as a ratio of two integers.
Simple“Pi is the most famous example of an irrational number.”
In context“The proof that the square root of two is irrational remains a fundamental exercise in introductory number theory.”
Antonyms - 03 C1 Advanced
n.a number that cannot be made by dividing two whole numbers.
n.a real number that cannot be expressed as a quotient of two integers.
Simple“In this math problem, you need to identify which of these values are irrationals.”
In context“The set of real numbers is composed of both rationals and irrationals, though the latter are far more numerous.”
SynonymsAntonyms
“When we are convinced that someone is wrong, we may conclude that they are biased or irrational .”
From Latin irratiōnālis, from ir- + ratiōnālis.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.