irrational

word

/ˌɪˈɹæʃənəɫ/
i-RA-shuh-nuhl
/ɪɹˈæʃənəl/
i-RA-shuh-nuhl

Definition

When something is irrational, it does not make sense or is not based on reason or logic. It often describes actions, thoughts, or feelings that are not reasonable.

Usage & Nuances

Often used in formal or academic contexts, but common in everyday speech too. Describes thoughts, fears, or decisions that lack logic. Common combinations: 'irrational fear', 'irrational decision'. Do not use for mathematical 'irrational numbers'—this is a different meaning.

Example Sentences

Her reaction seemed completely irrational to everyone.

basic

He made an irrational decision without thinking it through.

natural

Stop being irrational—there's no reason to panic.

natural

Sometimes, our minds have irrational worries that we can't control.

natural

His irrational fear of dogs makes it hard to walk in the park.

basic

It's irrational to be afraid of the dark when you know there's nothing there.

basic