Fortuitous means by chance, like a lucky accident. If you and your best friend's families happen to go on vacation to the same place at the same time, that’s a fortuitous coincidence!

Something fortuitous is random like an accident, but there’s no downside. A rock falling on your head is an accident, dollar bills falling on your head is fortuitous. The meaning of fortuitous is changing from "happening by chance" to "lucky chance" because people get it mixed up with fortunate. But watch out: If you say fortuitous to mean just plain lucky without the element of chance –– that's a usage error.

Definitions of fortuitous

adj occurring by happy chance

“profits were enhanced by a fortuitous drop in the cost of raw materials”
having unexpected good fortune

adj having no cause or apparent cause

fortuitous encounters--strange accidents of fortune”
causeless, uncaused
not deliberate

Sign up, it's free!

Whether you're a student, an educator, or a lifelong learner, can put you on the path to systematic vocabulary improvement.