serendipity
n. uncountablen. the feeling of finding something great by accident.
n. the occurrence of fortunate discoveries made unintentionally.
Finding that quiet bookshop was pure serendipity.
Their collaboration began by serendipity — both researchers reached for the same book in the library stacks.
The discovery of penicillin is often cited as an instance of scientific serendipity, though Fleming's prepared mind is what let him recognise the significance of a contaminated plate.
From Serendip (“variant of Serendib: Ceylon, Sri Lanka”) + -ity. Coined by English writer and politician Horace Walpole in 1754 based on the Persian story of The Three Princes of Serendip, who (Walpole wrote to a friend) were “always making discoveries, by accidents and sagacity, of things which they were not in quest of”.