having false or unrealistic beliefs or opinions: Senators who think they will get agreement on a comprehensive tax bill are delusional.
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.

Sometimes de·lu·sion·ar·y. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for delusional

unrealistic, confused, deranged, neurotic, senile, paranoid, pretentious

Examples from the Web for delusional

Contemporary Examples of delusional

Historical Examples of delusional

  • The second kind of insanity is called illusional or delusional.

  • But the rapt bard was blinded, as his utterances show, by what now almost appears to have been a fit of delusional insanity.

    The Brothers' War

    John Calvin Reed

  • She's just traded identities—and everything else she does—everything else—stems logically out of her delusional premise.

    That Sweet Little Old Lady

    Gordon Randall Garrett (AKA Mark Phillips)

  • In this study Freud shows out of what infantile forms of thought and instincts the delusional system was built up.

  • The "melancholic" is evidently Newington's "delusional" without his more accurate discrimination of symptoms.

    Benign Stupors

    August Hoch

Word Origin and History for delusional

1871, from delusion + -al (1).

Online Etymology Dictionary, © 2010 Douglas Harper