Serendipity 

"Is the effect by which one accidentally discovers something fortunate, especially while looking for something else entirely unrelated"

The word has been imported into many other languages (Portuguese "serendipicidade" or "serendipidade";  French  "sérendipicité" or "sérendipité" but also heureux hasard, "fortunate chance"; Italian "serendipità"; Dutch "serendipiteit"; German "Serendipität;" Swedish, Danish and Norwegian "serendipitet"; Romanian "serendipitate"; Spanish "serendipia"