delusional
- 01 B2 Upper Intermediate
adj.believing something that is not true, even when there is proof that you are wrong.
adj.holding idiosyncratic beliefs that are maintained despite being contradicted by reality or rational argument.
Simple“He was delusional if he thought he could finish the whole project in one day.”
In context“The CEO's delusional insistence that the company was profitable led to a complete lack of preparation for the upcoming audit.”
Synonyms - 02 C1 Advanced
adj.relating to a serious mental health condition where a person cannot tell what is real.
adj.pertaining to or characterised by clinical delusions as a symptom of a psychiatric disorder.
Simple“The patient was experiencing delusional thoughts and needed professional help.”
In context“The psychiatrist noted that the patient's delusional episodes were becoming more frequent and less responsive to the current medication dosage.”
Synonyms - 03 C2 Proficiency
n.a person who believes things that are not true.
n.an individual suffering from a delusion or a delusional disorder.
Simple“The book describes the tragic life of a delusional who believed he was a king.”
In context“In his early essays, the philosopher treats the delusional not as a patient to be cured, but as a subject with a unique perspective on reality.”
UsageThis noun use is relatively rare and can sound clinical or insensitive; the adjective is much more common.
“He is among a group of researchers studying how chatbots respond to delusional thinking to try to identify who might be most at risk.”
From delusion + -al.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.