- 1[countable] a false belief or opinion about yourself or your situation the delusions of the mentally ill Don't go getting delusions of grandeur (= a belief that you are more important than you actually are). He was suffering from paranoid delusions and hallucinations. Love can be nothing but a delusion.
- 2[uncountable] the act of believing or making yourself believe something that is not true He seems to have retreated into a world of fear and delusion.
Check pronunciation: delusion