superiority complex
noun [ C usually singular ] UK /suː.pɪə.riˈɒr.ɪ.ti ˌkɒm.pleks/ US /suː.pɪr.iˈɔːr.ə.t̬i ˌkɑːm.pleks/ informal
If you have a superiority complex, you believe that you are better, cleverer, or more important than other people.
A superiority complex is a psychological defense mechanism that compensates for an inferiority complex.