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

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

I hope I’m also not delusional enough to think that I have another song that even does half as well as this song.

From The Wall Street Journal

"You really have to be delusional to work in this industry for so many years and still believe it's going to work," Keable told the BBC.

From BBC

Related Words

• unrealistic