coincidental

[ koh-in-si-den-tl ]

/ koʊˌɪn sɪˈdɛn tl /

happening by or resulting from coincidence; by chance: a coincidental meeting.

existing or occurring at the same time.

Origin of coincidental

First recorded in 1790–1800; coincident + -al¹

co·in·ci·den·tal·ly, co·in·ci·dent·ly

[koh-in-si-duh nt-lee] /koʊˈɪn sɪ dənt li/, adverb non·co·in·ci·den·tal, adjective non·co·in·ci·den·tal·ly, adverb un·co·in·ci·den·tal, adjective

un·co·in·ci·den·tal·ly, adverb

This had the coincidental effect of filling the room to capacity for the preceding speaker, Rick Santorum.

On CPAC Day 2, the Libertarian Wing Takes Over |Michelle Cottle |March 8, 2014 |DAILY BEAST
“When I met her we were talking how coincidental it was,” Williams tells The Daily Beast.

Vanessa Williams, the First Black Miss America, On Nina Davuluri and Racism |Marlow Stern |September 21, 2013 |DAILY BEAST
Please be advised that launching this feature the day after Yom Kippur is not coincidental, but divine timing.

The Week in Apologies |Adam Hanft |October 10, 2008 |DAILY BEAST
This report is prepared from the actual visit of the relieving officer at the home of the applicant, and by coincidental inquiry.

Blackwood's Edinburgh Magazine, Volume 61, No. 377, March 1847 |Various

And that again the similarity in retouching to the upper right of Oswald's shoulder and head might be coincidental?

Warren Commission (7 of 26): Hearings Vol. VII (of 15) |The President's Commission on the Assassination of President Kennedy
The Witch is an eminently readable story of adventure of the coincidental kind.

Punch or the London Charivari, Vol. 147, November 11, 1914 |Various
His passing, and the coming of the easterly wind, were coincidental.

The Mutiny of the Elsinore |Jack London
Then there befell the household a series of coincidental labor problems that left them all at once without servants.

The Tyranny of Weakness |Charles Neville Buck

coincidental

/ (kəʊˌɪnsɪˈdɛntəl) /

of or happening by a coincidence; fortuitous