irrationally

[ ih-rash-uh-nl-ee, -rash-nl- ]

adverb

1. in a way that is contrary to reason or is not sensible; illogically:

   In firing a highly competent CEO without cause, the Board acted unlawfully, unreasonably, and irrationally.

   Stick to your simple calculation and logic, even when markets are behaving irrationally.

2. in a way that is driven by impulse or instinct rather than reason; without having or being able to use the faculty of reason:

   When a reporter started poking around, the suspect began acting irrationally and took off like a wild animal.

Other Words From

• non·ir·ra·tion·al·ly adverb

Word History and Origins

Origin of irrationally¹

First recorded in 1640–50; irrational ( def ) + -ly ( def )

Example Sentences

Because baseball fandom is built on this — on over-analysis; on mornings spent sifting box scores, comparing and irrationally concluding.

From Seattle Times

A few days before these shootings, I was setting up for a journalism event in the Central District and heard what I first irrationally thought were a flurry of fireworks.

From Seattle Times

His lawyer argued that the government group that evaluated Harry’s security needs acted irrationally and failed to follow its own policies that should have required a risk analysis of the duke’s safety.

From Seattle Times

I’ve become irrationally angry with those who have suggested that their courtship is some sort of elaborate public relations stunt.

From Los Angeles Times

The counterclaim also detailed Jackson’s account of a February 2022 incident where Palmer alleged that her ex-boyfriend became “violently jealous and irrationally angry over a bikini picture.”

From Los Angeles Times

Related Words

• foolishly
• stupidly
• unreasonably