from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Happening by accident or chance. See Synonyms at accidental.
  • adj. Usage Problem Happening by a fortunate accident or chance.
  • adj. Usage Problem Lucky or fortunate.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Happening by chance; coincidental or accidental.
  • adj. Happening by a lucky chance; lucky or fortunate.
  • adj. Happening independently of human will.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Happening by chance; coming or occuring unexpectedly, or without any known cause; chance.
  • adj. Happening independently of human will or means of foresight; resulting from unavoidable physical causes.

from The Century Dictionary and Cyclopedia

  • Accidental; casual; happening by chance; coming or occurring without any cause, or without any general cause; random.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. occurring by happy chance
  • adj. having no cause or apparent cause


from The American Heritage® Dictionary of the English Language, 4th Edition

Latin fortuītus.

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin fōrtuītus.


  • Hence there grew up the belief that events which we describe as fortuitous or random or subject to chance are no different from any other happenings, except that we do not know why they happen.


  • For very many in the world attribute everything to themselves and their prudence, and what they cannot so attribute they call fortuitous and accidental, not knowing that human prudence is nothing and that "fortuitous" and "accidental" are idle words.

    Angelic Wisdom about Divine Providence

  • The reliance on coincidence or the fortuitous is often questionable, but the results at the same time are never quite incredible.

    Great Scot

  • Krutak has been unemployed since quitting a job in July at a nonprofit, timing she called fortuitous in light of the Occupy movement.

    Yahoo! News: Business - Opinion

  • A careful induction from all the passages where this number cannot be regarded as fortuitous, but is evidently of Divine ordinance and appointment (I call fortuitous such sevens as occur, Acts xix. 14; xx. 6), will leave no doubt that it claims throughont Scripture to be considered as the covenant number, the sign and signature of God's covenant relation to mankind, and above all to that portion of mankind with which this relation is not potential merely, but actual, namely the Church.

    Epistles to the Seven Churches in Asia.

  • And he concludes, after referring to the fortuitous duty-free shopping interlude I shared with Bashar en route back to London from Damascus, by remarking: By this time, Michael, whos a very engaging personality, is a friend of the family!

    A Question of Honour

  • Yet all of the various elements which have historically been assigned to Fortune, Fate, and Chance are gathered into a single providential system of which the fortuitous is a part.


  • Since Fortuna is a personification of the fortuitous, and the fortuitous is a branch of the chain of causality, its normal place in the providential scheme is within the realm of Fate, which is the unfolding of Providence in multiplicity and time.


  • An event that is described as fortuitous or accidental in the context of one set of interests may take on a different aspect when it is surveyed from another standpoint, being seen there as intrinsically related to the historian's principal theme or subject: in neither case, though, need the suggestion that it has no causal explanation be present.


  • More probably the resemblance which may be traced in this respect between the religions of the East and West is no more than what we commonly, though incorrectly, call a fortuitous coincidence, the effect of similar causes acting alike on the similar constitution of the human mind in different countries and under different skies.

    Chapter 43. Dionysus


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  • occurring by happy chance; having no cause or apparent cause

    Though Maria's neighbor Ernie "bumped into" her at the Farmer's Market, the encounter wasn't nearly as fortuitous as Maria was led to believe: Ernie desperately wanted to ask Maria out on a date and had been following her about town.

    October 12, 2016

  • @TJay:

    Although some, seeking pomposity, substitute fortuitous for fortunate, the words are not synonymous. Fortunate means “lucky.” Fortuitous means “by chance,” “by accident.” Something that is fortuitous can also be fortunate, but unless it happened by chance, fortunate is the correct word.

    – Rene J. Cappon, The Associated Press Guide to Writing, Peterson’s, 2000

    That’s the usage problem to which the AHD entries refer. Until recently, “fortuitous” meant “accidental”, not “lucky”. (See the CDC definition.) In the twentieth century some English speakers began to conflate fortuitous with fortunate and using it to mean (as you say) serendipitous. Some audiences regard this usage as confused or pompous, and a good dictionary won’t include it without a warning.

    May 4, 2013

  • How can "serendipitous" not be a synonym for "fortuitous?"

    May 3, 2013

  • I've made a fortuitous mistake.

    January 22, 2013

  • Wasn't it fortuitous that John came up with the idea of Wordie?

    October 27, 2007

  • Pronunciation:

    \fȯr-ˈtü-ə-təs, -ˈtyü-, fər-\


    Latin fortuitus; akin to Latin fort-, fors chance



    1: occurring by chance

    a: fortunate, lucky

    b: coming or happening by a lucky chance

    October 27, 2007