'delusional' originates from Latin, specifically the word 'deludere,' where 'de-' meant 'away' and 'ludere' meant 'to play.'

'deludere' transformed into the French word 'délusion,' and eventually became the modern English word 'delusion' through Middle English.

Initially, it meant 'to deceive or play falsely,' but over time it evolved into its current meaning of 'having false beliefs.'