gringo (n.)

by 1841 as a term for a non-Latin European or Anglo-American, in a Chilean context, in reference to an Englishman; an 1831 English-language novel by author Telesforo de Trueba y Cosio includes a character "Mr. O'Gringo, an Irishman."

The word is from Castilian Spanish gringo "foreigner," perhaps ultimately from griego "Greek", but this may be folk etymology; compare French gringoter, "singing with a tremble in the throat; humming."

The claim that it is from a Mexican mishearing of American or Irish soldiers singing Green Grow the Rushes (or some variant on the title) has no factual basis. The word first appears in Spain. The Diccionario Castellano of 1787 reports the term gringos used for foreigners "who have a certain type of accent" and especially for "the Irish." An 1805 edition of Don Quixote footnotes that gringo is used as a term for Germans, Swiss, and people from "Northern nations." Hence the American Spanish verb engringarse "to act like a foreigner." In Spanish gringo could also mean any person who spoke Spanish poorly.