certain

1 of 2

adjective

cer·​tain ˈsər-tᵊn 

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

• anonymous
• given
• one
• some
• unidentified
• unnamed
• unspecified

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

Adjective

Love Jackie Mason for certain things… really don’t for others. —Mikey O'Connell, The Hollywood Reporter, 4 Apr. 2024

But the United States is again almost certain to block it. —NBC News, 4 Apr. 2024

Secondary cities To be sure, these hot housing markets could be second home purchases by wealthy Boston residents or primary home purchases by locals—there’s no way to tell for certain. —Alena Botros, Fortune, 4 Apr. 2024

No one knows for certain who invented the burrito, according to hightidetacobar.com. —Chris Sims, The Indianapolis Star, 4 Apr. 2024

While Muslims across the world will still have to wait till Monday night, to know for certain, the total solar eclipse and New Moon suggest requesting Wednesday off for Eid if a fair bet. —Sarah Al-Arshani, USA TODAY, 4 Apr. 2024

But So wasn’t entirely certain when one of Gordon’s researchers recently stopped by her house with a photograph of the carving. —Stephanie Yang, Los Angeles Times, 3 Apr. 2024

The porosity of your hair also influences how your hair will respond to certain products. —Janell Hickman-Kirby, Vogue, 3 Apr. 2024

Screening also offers an opportunity to catch certain cancers early, when the odds of survival are better and the treatments typically less harsh. —Karen Weintraub, USA TODAY, 23 Mar. 2024

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

Phrases Containing certain

• all but certain to
• make certain of
• to a certain extent
• make certain
• of a certain age
• under certain circumstances
• a certain
• for certain

Kids Definition

certain

1 of 2 adjective

cer·​tain ˈsərt-ᵊn 

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 my classmates are absent