The faculty of making fortunate discoveries by accident.
[From the characters in the Persian fairy tale The Three Princes of Serendip, from Persian Sarandip, Sri Lanka, from Arabic Sarandib]
Word history: We are indebted to the English author Horace Walpole for coining the word serendipity. In one of his 3,000 or more letters, on which his literary reputation rests, and specifically in a letter of January 28, 1754, Walpole says that "this discovery, indeed, is almost of that kind which I call Serendipity, a very expressive word." Perhaps the word itself came to him by serendipity. Walpole formed the world on an old name for Sri Lanka, Serendip. He explained that this name was part of the title of a "silly fairy tale, called The Three Princes of Serendip; as their highnesses travelled, they were always making discoveries, by accidents and sagacity, of things which they were not in quest of ... One of the most remarkable instances of this accidental sagacity (for you must observe that no discovery of a thing you are looking for comes under this description) was of my Lard Shaftsbury, who happening to dine at Lord Chancellor Claredon's, found out the marriage of the Duke of York and Mrs. Hyde, by the respect with which her mother treated her at table."
SERENDIPITY (from the Oxford English Dictionary)
f. Serendip, a former name for Sri Lanka + -ity. A word coined by Horace Walpole, who says (Let. to Mann, 28 Jan. 1754) that he had formed it upon the title of the fairy-tale `The Three Princes of Serendip', the heroes of which `were always making discoveries, by accidents and sagacity, of things they were not in quest of'.
The faculty of making happy and unexpected discoveries by accident. Also, the fact or an instance of such a discovery. Formerly rare, this word and its derivatives have had wide currency in the 20th century.
* 1955 Sci. Amer. Apr. 92/1 Our story has as its critical episode one of those coincidences that show how discovery often depends on chance, or rather on what has been called `serendipity'-the chance observation falling on a receptive eye.
* 1971 S. E. Morison European Discovery Amer.: Northern Voy. i. 3 Columbus and Cabot..(by the greatest serendipity of history) discovered America instead of reaching the Indies.
* 1980 TWA Ambassador Oct. 47/2 It becomes a glum bureaucracy, instead of the serendipity of 30 people putting out a magazine.
* 1939 Joyce Finnegans Wake 191 You..semisemitic serendipitist, you (thanks, I think that describes you) Europasianised Afferyank!
* 1968 Punch 13 Nov. 684/1 There are the financial serendipitists, the men blessed monetarily by a fortunate law.