cock·​sure ˈkäk-ˈshu̇r How to pronounce cocksure (audio)
: feeling perfect assurance sometimes on inadequate grounds
: marked by overconfidence or presumptuousness : cocky
cocksurely adverb
cocksureness noun
Choose the Right Synonym for cocksure

sure, certain, positive, cocksure mean having no doubt or uncertainty.

sure usually stresses the subjective or intuitive feeling of assurance.

felt sure that I had forgotten something

certain may apply to a basing of a conclusion or conviction on definite grounds or indubitable evidence.

police are certain about the cause of the fire

positive intensifies sureness or certainty and may imply opinionated conviction or forceful expression of it.

I'm positive that's the person I saw

cocksure implies presumptuous or careless positiveness.

you're always so cocksure about everything

Examples of cocksure in a Sentence

you're always so cocksure about everything
Recent Examples on the Web No brand should be so cocksure as to presume its products are irreplaceable. Cate Rubenstein, Rolling Stone, 11 Jan. 2023 Nayeri’s demeanor — usually cocksure — became unhinged. Tim Dickinson, Rolling Stone, 17 Dec. 2022 Yann Gael, Roger Sallah and Mentor Ba entertain as tough guy gunslingers, but their cocksure attitude is tested when a paranormal foe threatens them and their stash of gold. Thomas Page, CNN, 23 Sep. 2022 From the start, Mr. Koecher was at once brilliant and hard to take—cocksure and certain that he was destined for great things. Edward Kosner, WSJ, 25 Aug. 2022 Amid the cocksure bravado of the adventure-sports world, fluidity is read as weakness. Alison Van Houten, Outside Online, 22 Aug. 2020 So cocksure are they, even their hair seems to swagger. San Diego Union-Tribune, 8 May 2022 Craig Kilborn, the fratty cocksure original host of The Daily Show, had gotten his big call-up from CBS to host the late-night slot following David Letterman’s, which was one of two jobs Stewart didn’t get. Devin Gordon, The Atlantic, 21 Apr. 2022 After the evacuation, the four Brits were skewered as irresponsible and cocksure by Icelanders and media outlets around the world. Devon O’Neil, Outside Online, 20 Apr. 2016

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cocksure.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


probably from cock entry 1 + sure

First Known Use

1672, in the meaning defined at sense 1

Time Traveler
The first known use of cocksure was in 1672

Dictionary Entries Near cocksure

Cite this Entry

“Cocksure.” Dictionary, Merriam-Webster, Accessed 15 Jun. 2024.

Kids Definition


cock·​sure ˈkäk-ˈshu̇(ə)r How to pronounce cocksure (audio)
: perfectly sure : certain
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