To be a conservative is to want to conserve, to hang onto, the patrimony, cultural, political, social, religious,... of one's civilization, and to view proposals for change skeptically, measuring them against that patrimony.
In the American (and British) context, this means as a practical matter, hanging onto the patrimony of Western Civilization (or Christendom, if you will), up to and including the Anglo-Scottish Enlightenment, of which the American Founding was the beneficiary, while resisting Jacobinism and all the baleful enthusiasms of the Continental "Enlightenment" that have generally borne the name "left", which seek to tear down that patrimony on behalf of some vision of a shining new future. The political tradition of conservatism has many notable figures on both sides of the Atlantic -- before the American Founders, there was John Locke, contemporaneous with the American Founding, Edmund Burke upheld the same tradition in your country, as, later, did Lord Acton, more recently Russell Kirk and William F. Buckley, Jr. upheld it here in the States. I think the more intellectually astute of your "Brexiteers" (Jacob Rees-Mogg comes to mind) stand firmly within the conservative tradition as it is found in the Anglosphere.
A conservative anywhere in the erstwhile Christendom (or former colonies of European Christian powers that embraced their culture) will have a sense of the imperfectiblity of Man, rooted in the doctrine of the Fall and the Church's rejection of Pelagianism, and thus, unless he still hangs onto the idea of the divine right of kings and expects an annointed Christian king to have some special grace to govern well, historical experience notwithstanding, will be skeptical of all concentrations of power (or at least of secular power).