quixotic

First recorded in 1805–15; (Don) Quixote + -ic

Miguel de Cervantes’ novel El Ingenioso Hidalgo Don Quixote de la Mancha ( The Ingenious Gentleman Sir Quixote of La Mancha ), or simply, in English, Don Quixote, was published in two parts, in 1605 and 1615. Full or partial translations of the first part of Don Quixote appeared in English (and French, Italian, and German) by 1612. An English translation of the second part appeared in 1620.
By 1644 Quixote was used as a common noun, that is, “a person inspired by lofty and chivalrous but impractical ideals.” The derivative adjective quixotic, which applies to both persons and actions, appears in the first half of the 18th century. Quixotic has always been ambivalent in its meaning, whether “extravagantly chivalrous or romantic; visionary or impractical,” or “impulsive and often rashly unpredictable.”
The original 17th-century spelling that Cervantes used was Quixote, at that time pronounced kiˈshoʊ-ti (French Quichotte and Italian Chisciotte still maintain the sh- sound). In 1815 the Real Academia Española (Royal Spanish Academy) officially changed the spellings of words with x to j to match the change of the sh- sound to the modern Castilian x- sound, as in Johann Sebastian Bach (bɑx) or the Scots pronunciation of loch (lɒx).
To an American ear, the Don in Don Quixote may come across as the man’s first name, but that is certainly not the case here. In Spanish, don is used as a title of respect and as a common noun meaning “gentleman,” a most appropriate description for Cervantes’ iconic hero. Don, which ultimately derives from Latin dominus “lord, master,” is also familiar as the courtesy title of the head of a crime family or syndicate, especially the Mafia (as in Don Corleone). Don evokes courtesy and respect in England as well, where it is used colloquially at Oxbridge for a head, fellow, or tutor of a college.