Origin and history of Whig

"female of the horse or any other equine animal," Old English meare, also mere (Mercian), myre (West Saxon), fem. of mearh "horse," from Proto-Germanic *marhijo- "female horse" (source also of Old Saxon meriha, Old Norse merr, Old Frisian merrie, Dutch merrie, Old High German meriha, German Mähre "mare"), said to be of Gaulish origin (compare Irish and Gaelic marc, Welsh march, Breton marh "horse").

The fem. form is not recorded in Gothic, and there are no known cognates beyond Germanic and Celtic, so perhaps it is a word from a substrate language. The masc. forms have disappeared in English and German except as disguised in marshal (n.). In 14c. also "a bad woman, a slut," and, apparently, also "a rabbit." As the name of a throw in wrestling, it is attested from c. 1600. Mare's nest "illusory discovery, something of apparent importance causing excitement but which turns out to be a delusion or a hoax" is from 1610s.

1566, in English state papers, "an Irish outlaw," in 17c. especially one of a class of Irish robbers noted for outrages upon English settlers and savage cruelty, from Irish toruighe "plunderer," originally "pursuer, searcher," from Old Irish toirighim "I pursue," from toir "pursuit," from Celtic *to-wo-ret- "a running up to," from PIE root *ret- "to run, roll" (see rotary). It also was used of a hector or bully, and of robbers or bandits generally.

About 1646, it emerged as a derogatory term for Irish Catholics dispossessed of their land (some of whom subsequently turned to outlawry); c. 1680 it was applied by Exclusioners to supporters of the Catholic Duke of York (later James II) in the dispute over his succession to the throne of England.

After 1689, Tory (with a capital) was the name of a British political party at first composed of Yorkist Tories of 1680; it also included the political descendants of the Cavaliers and Royalists and served as the Court party (compare Whig). As a name it was superseded c. 1830 by Conservative, though it continues to be used colloquially.

[H]e who draws his pen for one party must expect to make enemies of the other. For wit and fool are consequents of Whig and Tory ; and every man is a knave or an ass to the contrary side. [Dryden, "Absalom & Achitophel," 1681]

Thus vaguely "a conservative," or anyone who supports the continuance of established authorities and institutions or has aristocratic principles (opposed to a liberal or democrat). In American history, Tory was the name applied after 1769 to colonists who remained loyal to the crown; it represents their relative position in the pre-revolutionary political order in the English colonies.

A Tory has been properly defined to be a traitor in thought, but not in deed. The only description, by which the laws have endeavoured to come at them, was that of non-jurors, or persons refusing to take the oath of fidelity to the state. [Jefferson, "Notes on the State of Virginia"]

As an adjective, "pertaining to or characteristic of the Tory party," from 1680s. Related: Toryism; Torify.