[ ˌsɛr(ə)n'dɪpɪti ]
■ noun the occurrence and development of events by chance in a happy or beneficial way.
Derivatives
serendipitous adjective
serendipitously adverb
Origin
1754: coined by Horace Walpole, suggested by The Three Princes of Serendip , the title of a fairy tale in which the heroes were always making fortunate discoveries.