[ fawr-too-i-tuhs, -tyoo- ]
/ fɔrˈtu ɪ təs, -ˈtyu- /


happening or produced by chance; accidental: a fortuitous encounter.
lucky; fortunate: a series of fortuitous events that advanced her career.

Origin of fortuitous

1645–55; < Latin fortuitus, fortuītus, equivalent to fortu- (u-stem base, otherwise unattested, akin to fors, genitive fortis chance, luck) + -itus, -ītus adj. suffix (for formation cf. gratuitous); see -ous

Related forms

Can be confused

felicitous fortuitous fortunate (see usage note at the current entry)

Synonym study

1. See accidental.

Usage note

Fortuitous has developed in sense from “happening by chance” to “happening by lucky chance” to simply “lucky, fortunate.” This development was probably influenced by the similarity of fortuitous to fortunate and perhaps to felicitous : A fortuitous late-night snowfall made for a day of great skiing.
Many object to the use of fortuitous to mean simply “fortunate” and insist that it should be limited to its original sense of “accidental.” In modern standard use, however, fortuitous almost always carries the senses both of accident or chance and luck or fortune. It is infrequently used in its sense of “accidental” without the suggestion of good luck, and even less frequently in the sense “lucky” without at least a suggestion of accident or chance: A fortuitous encounter with a former schoolmate led to a new and successful career for the artist. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fortuitous

British Dictionary definitions for fortuitous


/ (fɔːˈtjuːɪtəs) /


happening by chance, esp by a lucky chance; unplanned; accidental

Derived Forms

fortuitously, adverbfortuitousness, noun

Word Origin for fortuitous

C17: from Latin fortuitus happening by chance, from forte by chance, from fors chance, luck
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012