HanoverianPronunciation: /ˌhanə(ʊ)ˈvɪərɪən/Definition of Hanoverian adjective relating to the royal house of Hanover. noun 1 (usually the Hanoverians) any of the British sovereigns from George I to Victoria. 2a medium-built horse of a German breed, developed for use both as a riding horse and in harness. Hanoverian in other Oxford dictionaries Definition of Hanoverian in the US English dictionary