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

Pigments are the chemical substances in animal and plant cells that impart color, absorb and reflect certain wavelengths of light. —Karina Zaiets, USA TODAY, 27 Apr. 2024

Elliott took a sizable position in BHP in 2017 and pushed it to spin off certain oil assets. —Crystal Tse, Fortune, 27 Apr. 2024

Other food labels may include molasses, rice syrup, agave nectar, and high fructose corn syrup (a contributing factor in metabolic diseases and even certain cancers). —Shereen Lehman, Ms, Verywell Health, 27 Apr. 2024

Redstone, according to one person familiar with the matter, has also been frustrated with certain of Bakish’s decisions, including not selling Showtime. —Samantha Masunaga, Los Angeles Times, 27 Apr. 2024

Last week, the California Senate Public Safety Committee rejected a bipartisan bill banning camping in certain public places if shelter space is available. —Michael Smolens, San Diego Union-Tribune, 26 Apr. 2024

The research builds on other studies that have found high PFAS levels in certain seafood species, Tracey Woodruff, PhD, MPH, director of the Program on Reproductive Health and the Environment at the University of California, San Francisco, told Health. —Brian Mastroianni, Health, 26 Apr. 2024

Poultry producers will be required to bring salmonella bacteria in certain chicken products to very low levels to help prevent food poisoning under a final rule issued Friday by U.S. agriculture officials. —CBS News, 26 Apr. 2024

While the West is ruling out participating in a military response, an economic response to Iran’s actions appears increasingly certain. —Jeff Stein, Washington Post, 16 Apr. 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

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

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