de‧lu‧sion / dɪˈluːʒ ə n / noun
1 [ uncountable and countable ] a false belief about yourself or the situation you are inunder a delusion (that)He is under the delusion that I am going to cheat him.
2 delusions of grandeur the belief that you are much more important or powerful than you really are
- delusive / -sɪv / adjective
- delusional adjective
something that is untrue
myth something a lot of people believe because they want to believe it, not because it is based on fact : The first myth about motherhood is that new mothers instantly fall in love with their babies. | Contrary to popular myth , our streets are much safer now than they were 100 years ago.
illusion a belief or idea that is false, especially a belief in something good about yourself or about the situation you are in : Alcohol gives people the illusion of being witty and confident. | People bought the land under the illusion that the value would increase.
misconception an idea that is not true but which people believe because they do not have all the facts, or they have not properly understood the situation : It's a common misconception that vaccinations given in childhood last for life. | Employers seem to share the general misconception that young people are more efficient than older workers.
delusion a completely mistaken idea, which affects your behaviour and what you decide to do : He began to suffer from paranoid delusions. | Many people labour under the delusion (= have the delusion ) that anything which says 'natural ingredients' on the label must be harmless. | the delusion that women control most of the world' s wealth and power
fallacy if you say that something is a fallacy, you mean that it is completely wrong to believe that it is true : The idea that a good night's sleep will cure everything is a complete fallacy. | It's a fallacy that all fat people are fat simply because they eat too much.