Definition of Brexiter in English:

Brexiter

Pronunciation /ˈbreksədər/ /ˈbrɛksədər/

noun

informal British
  • A person who is in favor of the United Kingdom withdrawing from the European Union.

    • ‘many Brexiters would like to follow the Norwegian model’
    • ‘this was not another scary intervention in the referendum debate by a pro-European or a Brexiter’

Origin

Early 21st century from Brexit + -er.