British political party, 1657, in part perhaps a disparaging use of
whigg "a country bumpkin" (c.1645); but mainly a shortened form of
Whiggamore (1649) "one of the adherents of the Presbyterian cause in western Scotland who marched on Edinburgh in 1648 to oppose Charles I." Perhaps originally "a horse drover," from dialectal verb
whig "to urge forward" +
mare. The name was first used 1689 in reference to members of the British political party that opposed the Tories. American Revolution sense of "colonist who opposes Crown policies" is from 1768. Later it was applied to opponents of Andrew Jackson (1825), and taken as the name of a political party (1834) that merged into the Republican Party in 1854-56.
Whig historian "one who views history as an inevitable march of progress" is recorded from 1924.