Definition of "Brexiteer"
Brexiteer
noun
plural Brexiteers
(UK politics) Someone who supports Brexit, the United Kingdom's exit from the European Union.
Quotations
Whether you are a Europhile or a Brexiteer, it’s hard to see what’s not to like about a market-driven initiative that aims to pull down barriers to more investment across Europe.
2015 October 4, William Wright, “A plan from Brussels where Britain can take the lead”, in The Daily Telegraph, London, archived from the original on 9 November 2018
Denying he [David Cameron] was a "closet Brexiteer", as his former aide Steve Hilton has claimed, the PM told reporters: "I withdraw absolutely nothing I've previously said. Britain is an amazing country. We can find our way whatever the British people choose.
2016 May 27, “David Cameron: I am not a closet Brexiteer”, in The Herald, Glasgow
A leading Tory Brexiteer has insisted quitting the EU does not mean the numbers of people coming to Britain will be slashed – and claimed Vote Leave never said it would.
2016 June 25, Tim Sculthorpe, “Tory Brexiteer Dan Hannan insists quitting the EU does NOT mean dramatic cuts to the number of immigrants coming to Britain”, in Daily Mail, London, archived from the original on 26 June 2016
(UK politics) Usually in plural: a holder of any of the posts in the British Cabinet tasked with negotiating the country's exit from the European Union.
Quotations
For newspapers with only the Olympics to write about during August, the squabbling "Three Brexiteers" – the senior ministers supposedly tasked with executing the will of the British people to remove us from the European Union – came as a gift.
2016 September 7, Simon Heffer, “The Three Brexiteers”, in New Statesman, London, published 9–15 September 2016, archived from the original on 20 October 2018
She [British Prime Minister Theresa May] urges people to get behind the team of ministers working for Brexit: David Davis, Liam Fox, Priti Patel and Boris Johnson. (It seems Patel has now been co-opted as a fourth Brexiteer.)
2016 October 2, Andrew Sparrow, “May says workers’ rights will be protected as long as she is PM – Politics live”, in The Guardian, London, archived from the original on 6 January 2017
That was until she announced that Boris Johnson would have to share Chevening, the foreign secretary’s grace-and-favour country retreat, with his fellow cabinet Brexiteers, David Davis and Liam Fox.
2016 October 31, Matt Chorley, “Bluster, bickering and three Brexiteers: Stage is set for a satire made in heaven: Yes Minister creator finds comic gold among Chevening’s trio of new tenants”, in The Times, London, archived from the original on 8 January 2017
It's worth remembering all the Three Brexiteers, who campaigned to Leave, are still in place.
2017 June 11, Anoosh Chakelian, “Government reshuffle: Who’s who in Theresa May’s new team?: While attempting to cling on to power, the Prime Minister is making some new appointments”, in New Statesman, London, archived from the original on 15 August 2017
At the moment, our future is being decided by Theresa May’s desperate attempts to remain as prime minister (and to do this she has to kowtow to the wishes of the three Brexiteers Boris Johnson, David Davis, and Jacob Rees-Mogg). The future, therefore, is not being decided by us.
2018 August 11, Athian Akec, “As a 15-year-old youth MP, I can tell you why ignoring our young people on the final Brexit deal will be a disaster”, in The Independent, London, archived from the original on 15 August 2018