quantum supremacyEnglishOxford Dictionary of Englishquantum supremacy /ˌkwɒntəm sʊˈprɛməsi , ˌkwɒntəm suːˈprɛməsi / ▸ noun [mass noun] the demonstrable ability of a quantum computer to solve a problem that an ordinary computer could not solve in a realistic amount of time: this feat of quantum supremacy signalled a new era of ultrafast computing.