Irrational
/ɪˈræʃənəl/
Definitions
2 meaningsNot logical or reasonable; lacking the power of reason; contrary to reason.
/ɪˈræʃənəl/
Lacking reason or understanding
It was irrational to think that he could win the race without training.
💡 Simply: When someone's acting irrational, it's like they're not making sense or not thinking things through clearly. Think of a kid throwing a tantrum for no good reason, or someone making a decision without considering the consequences—that's irrational behavior!
👶 For kids: When something is irrational, it doesn't make any sense and it's not fair.
More Examples
Her fear of heights was an irrational phobia.
The stock market's response was irrational and unpredictable.
How It's Used
"Irrational fears can significantly impact a person's daily life."
"The market's irrational exuberance led to a speculative bubble."
(Mathematics) (of a number or quantity) not expressible as a ratio of two integers.
/ɪˈræʃənəl/
Not governed by or according to reason.
Pi (π) is a classic example of an irrational number.
💡 Simply: In math, an irrational number is like a number that goes on forever without repeating, like the square root of 2, or pi. You can't write it down exactly as a fraction. It's a bit like a mystery!
👶 For kids: In math, some numbers are like forever-going numbers that can’t be cut into equal pieces.
More Examples
The square root of 3 is an irrational number.
The set of irrational numbers is denoted by the symbol 'I'.
How It's Used
"The square root of 2 is an irrational number."
From Latin *irrationalis*, from *in-* (not) + *rationalis* (rational). It first appeared in English in the late 16th century.
The term gained prominence in philosophical and mathematical discussions in the 17th and 18th centuries.
Memory tip
Imagine an *ir*responsible person acting without a plan, exhibiting *rational* thought.
Word Origin
"not rational; unreasonable"