Etymology: L, nomen, name, clamare, to call. a consistent, systematic method of naming used in a scientific discipline to denote classifications and avoid ambiguities in names, such as binomial nomenclature in biology and chemical nomenclature in chemistry.
To Easterners, a Yankee is a New Englander. To New Englanders, a Yankee is a Vermonter. And in Vermont, a Yankee is somebody who eats pie for breakfast.. This quote sums up pretty well how Yankees is really a contextual phrase.
Within the United States, Yankee usually refers to people specifically from New England or the Northern United States, though it has been applied to Americans generally since the 18th century, especially by the British. The earliest recorded use in this context is in a 1784 letter by Horatio Nelson.