Irrational
Synonyms: Unreasonable, groundless, unfounded, unsound, ridiculous, silly, senseless, laughable, stupid, untenable, unscientific, crazy, barmy, backasswards, illogical, baseless, unjustifiable, absurd, ludicrous, foolish, nonsensical, idiotic, wild, implausible, arbitrary, mad, and daft.
Example Sentences
His fear of harmless insects is completely irrational.
She made an irrational decision in the heat of the moment.
It's irrational to panic over something so small.
He had an irrational hatred for the color blue.
Her irrational behavior worried her friends.
The argument was based on irrational beliefs.
He gave an irrational response to a simple question.
Irrational thoughts kept her up all night.
Their fear of failure became irrational.
The plan was rejected due to its irrational risks.