certain

1 of 2

adjective

cer·​tain ˈsər-tᵊn How to pronounce certain (audio)
Synonyms of certainnext
1
: fixed, settled
a certain percentage of the profit
2
: of a specific but unspecified character, quantity, or degree
the house has a certain charm
3
a
: dependable, reliable
a certain remedy for the disease
b
: known or proved to be true : indisputable
it is certain that we exist
4
a
: inevitable
the certain advance of age
b
: incapable of failing : destined
—used with a following infinitive
she is certain to do well
5
: assured in mind or action
I am certain they are right

certain

2 of 2

pronoun

plural in construction
: certain ones
certain of my generation—W. B. Yeats
Phrases
for certain
: as a certainty : assuredly
the cause is not known for certain
of a certain age
: of a somewhat advanced age : no longer young
remembered by people of a certain age

Synonyms

Adjective

See all Synonyms & Antonyms in Thesaurus 
Choose the Right Synonym for certain

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 certain in a Sentence

Adjective I'm fairly certain that I'll be on time. a certain person told me that today is your birthday
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
Calcium and vitamin D Osteoporosis cannot be completely cured, but certain lifestyle and dietary factors can lower your risk. —Jianying Zhang, Discover Magazine, 8 Nov. 2024 In addition, family discussions related to entertaining at home or dealing with certain repairs are likely. —Georgia Nicols, The Denver Post, 8 Nov. 2024 But with the Trumps, Musk also may have found a sense of family that has eluded him in certain ways. —Martha Ross, The Mercury News, 7 Nov. 2024 When to Go Mobile There are certain circumstances that will lead you to mobile hunting. —Josh Honeycutt, Outdoor Life, 7 Nov. 2024 See all Example Sentences for certain 

Word History

Etymology

Adjective

Middle English certeyn, certayne, borrowed from Anglo-French certein, certain, going back to Vulgar Latin *certānus, from Latin certus "fixed, settled, indisputable," originally past participle of cernere "to sift, discern, decide, determine" (going back to an Indo-European present stem *kri-n-, verbal adjective *kri-to-, from a verbal base *krei̯̯̯(h1)- "sift, separate," whence Greek krī́nein "to separate, choose, decide," verbal adjective kritós, Welsh gogrynu "to sift") + -ānus + -an entry 2

Pronoun

Middle English certyn, derivative of certeyn certain entry 1

First Known Use

Adjective

13th century, in the meaning defined at sense 1

Pronoun

15th century, in the meaning defined above

Time Traveler
The first known use of certain was in the 13th century

Phrases Containing certain

Dictionary Entries Near certain

cert

certain

certainly

See More Nearby Entries 

Cite this Entry

“Certain.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/certain. Accessed 23 Nov. 2024.

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Kids Definition

certain

1 of 2 adjective
cer·​tain ˈsərt-ᵊn How to pronounce certain (audio)
1
: fixed sense 1b
receive a certain share of the profits
2
: not to be doubted : known to be true
it is certain that diamonds are hard
3
: known but not named
a certain person told me
4
: reliable, sure
a certain cure
5
a
: sure to happen : bound to occur : inevitable
defeat was certain
b
: decided in advance by or as if by fate
the plan was certain to succeed
6
: assured in mind or action
feel certain they will come

certain

2 of 2 pronoun
: certain ones
certain of them attended

More from Merriam-Webster on certain

Nglish: Translation of certain for Spanish Speakers

Britannica English: Translation of certain for Arabic Speakers

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