having no cause or apparent cause; "a causeless miracle"; "fortuitous encounters--strange accidents of fortune"; "we cannot regard artistic invention as uncaused and unrelated to the times"
You can describe something as fortuitous if it happens, by chance, to be very successful or pleasant. Their success is the result of a fortuitous combination of circumstances. = lucky. happening by chance, especially in a way that has a good result (fortuitus, from fors )
occurring by happy chance; "profits were enhanced by a fortuitous drop in the cost of raw materials
Happening independently of human will or means of foresight; resulting from unavoidable physical causes
Happening by chance; coming or occuring unexpectedly, or without any known cause; chance; as, the fortuitous concourse of atoms
occurring by happy chance; "profits were enhanced by a fortuitous drop in the cost of raw materials"
\for-TOO-uh-tuhs; -TYOO-\, adjective: 1 Happening by chance; coming or occurring by accident, or without any known cause 2 Happening by a fortunate or lucky chance 3 Fortunate or lucky