delusional

American  

[dih-loo-zhuh-nl] / dɪˈlu ʒə nl /

Sometimes delusionary

adjective

1. having false or unrealistic beliefs or opinions.

   Senators who think they will get agreement on a comprehensive tax bill are delusional.

2. Psychiatry. maintaining fixed false beliefs even when confronted with facts, usually as a result of mental illness.

   He was so delusional and paranoid that he thought everybody was conspiring against him.

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Etymology

Origin of delusional

First recorded in 1850–60; delusion ( def. ) + -al ¹ ( def. )

Example Sentences

To start their companies, founders have to be creative, restless, slightly delusional and outrageously ambitious.

From The Wall Street Journal

“And you don’t hate being stuck with a partner,” Elliot said, making it very clear in his tone that he thought Corban was delusional.

From Literature

Numerous studies have found that in its eagerness to agree with the user, the model validated unhealthy or dangerous behaviour, and even led people to delusional thinking.

From BBC

While the “number of users” once meant “number of paying users,” the success of Facebook, Instagram and other social-media sites persuaded delusional investors that the word “paying” could be dropped.

From MarketWatch

Pimenta argues that agents who still feel they can do everything are either 'delusional' or making promises they can't keep.

From BBC

Related Words

• unrealistic