serendipityˌ sɛr(ə)nˈdɪpɪti/ noun
  1. the occurrence and development of events by chance in a happy or beneficial way.
Serendipity means a “fortunate or happy unplanned coincidence”. The term was coined by Horace Walpole in 1754. In a letter he wrote to his friend Horace Mann, Walpole explained an unexpected discovery he had made about a (lost) painting of Bianca Cappello by Giorgio Vasari by reference to a Persian fairy tale, The Three Princes of Serendip. The princes, he told his correspondent, were “always making discoveries, by accidents and sagacity, of things which they were not in quest of”.