irrational

Definitions

Not endowed with the power of reason.

Not based on or governed by logic or sound judgment.

In mathematics, a number that cannot be expressed as a ratio of two integers.

Examples

It is irrational to be afraid of something that poses no real threat.

The mathematician proved that the square root of two is an irrational number.

Synonyms

illogical unreasonable senseless absurd foolish nonsensical unfounded

Antonyms

logical rational reasonable sensible sound coherent justified