In an irrational manner; without reason; in a manner contrary to reason; absurdly.(adverb)
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Use "irrationally" in a sentence
"He might have a point to a degree, but, comically, the rather obvious thing he has overlooked is that a forum devoted to atheism attracts a lot of people who are more interested in irrationally venting their spleen than in calm reasoned argument."
"Drunks do it drunkenly, which is to say irrationally and against what would otherwise be their better judgment."
"2B The Unabomber writes that society evolves irrationally, which is probably how he justified mailing people bombs."
"Overall, I agree with Friedman that evolutionary psychology can provide insights into the factors that lead people to behave "irrationally" in markets and in their beliefs about markets."
"I think it is true that people make political and economic decisions "irrationally" in the sense those decisions are often motivated by the desire for validation."