Yăn'kee, n.
(yănk'e), n. [Commonly considered to be a corrupt pronunciation of the word English, or of the French word Anglais, by the native Indians of America. According to Thierry, a corruption of Jankin, a diminutive of John, a nickname given to the English colonists of Connecticut by the Dutch settlers of New York. Dr. Wm. Gordon (Hist. of the Amer. War, ed. 1789, vol. i., pp. 324, 325) says it was a favorite cant word in Cambridge, Mass., as early as 1713, and that it meant excellent; as, a yankee good horse, yankee good cider, &c. He supposes that it was adopted by the students there as a by-word, and, being carried by them from the college, obtained currency in the other New England colonies, until at length it was taken up in other parts of the country, and applied to New Englanders generally, as a term of slight reproach. Cf. Scot. yankie, a sharp, clever, and rather bold woman, and Prov. Eng. bow-yankees, a kind of leggins worn by agricultural laborers.] A citizen of New England; also, a citizen of the Northern States, or a citizen of the United States;—a cant name, with a tinge of reproach in it, applied by foreigners to all inhabitants of the United States, and by the inhabitants of the seceded States (since the outbreak of the rebellion of 1861) to all those who remain loyal to the government.
From meanness first this Portsmouth Yankey rose, And still to meanness all his conduct flows. Oppression, A Poem by an American (Boston, 1765).