i ‧ deal ‧ is ‧ m /aɪˈdɪəlɪz ə m/ BrE AmE noun [uncountable]
1 . the belief that you should live your life according to high standards and principles, even when they are very difficult to achieve ⇨ realism :
the idealism of the younger generation
religious idealism
2 . technical a way of using art or literature to show the world as a perfect place, even though it is not ⇨ realism , naturalism