This is an interesting word because we can actually trace it back to one person who invented it. A man named Horace Walpole used it in a letter to a friend in 1754 to describe the characters in an old fairy tale, The Three Princes of Serendip. The main characters “were always making discoveries, by accidents and sagacity, of things they were not in quest of.” This is where we get the definition of the word ‘an aptitude for making desirable discoveries by accident’.
We can trace the origins of the word back a little further. The word Serendip is an old name for Ceylon, which is now Sri Lanka. This comes from the Arabic Sarandib (also referring to Sri Lanka) which comes from the Sanskrit word Suvarnadweepa, meaning ‘golden island’.