certain

[ sur-tn ]

adjective

1. free from doubt or reservation; confident; sure:

   I am certain he will come.

   Synonyms: satisfied

2. destined; sure to happen (usually followed by an infinitive):

   He is certain to be there.

3. inevitable; bound to come:

   They realized then that war was certain.

4. established as true or sure; unquestionable; indisputable:

   It is certain that he tried.

   Synonyms: clear, plain, obvious, incontrovertible, irrefutable, incontestable, indubitable

5. fixed; agreed upon; settled:

   on a certain day; for a certain amount.

   Synonyms: determined

6. definite or particular, but not named or specified:

   A certain person phoned. He had a certain charm.

7. that may be depended on; trustworthy; unfailing; reliable:

   His aim was certain.

8. some though not much:

   a certain reluctance.

9. Obsolete. steadfast.

pronoun

1. certain ones:

   Certain of the members declined the invitation.

certain

/ ˈsɜːtən /

adjective

1. postpositive positive and confident about the truth of something; convinced

   I am certain that he wrote a book

2. usually postpositive definitely known

   it is certain that they were on the bus

3. usually postpositive sure; bound; destined

   he was certain to fail

4. decided or settled upon; fixed

   the date is already certain for the invasion

5. unfailing; reliable

   his judgment is certain

6. moderate or minimum

   to a certain extent

7. make certain of
   to ensure (that one will get something); confirm

adverb

1. for certain
   definitely; without a doubt

   he will win for certain

determiner

1. 1. known but not specified or named

      certain people may doubt this

   2. ( as pronoun; functioning as plural )

      certain of the members have not paid their subscriptions

2. named but not known

   he had written to a certain Mrs Smith

Word History and Origins

Origin of certain¹

First recorded in 1250–1300; Middle English, from Old French, from Vulgar Latin certānus (unrecorded), from Latin cert(us) “sure, settled” (adjective use of past participle of cernere “to decide, separate, sift”) + -ānus -an

Word History and Origins

Origin of certain¹

C13: from Old French, from Latin certus sure, fixed, from cernere to discern, decide

Idioms and Phrases

Idioms

1. for certain, without a doubt; surely:

   I know for certain that I have seen that face before.

More idioms and phrases containing certain

see for certain .

Example Sentences

Applicants need to have a certain amount of cash savings — or what Canada calls “settlement funds” — to apply for Express Entry.

From Salon

Kennedy’s own accession to the HHS secretary post is not yet certain.

From Los Angeles Times

Two sources said last month that sheriff’s officials appeared to be taking interest, reviewing time sheets from certain units and asking pointed questions about outside employment.

From Los Angeles Times

In this system, each state gets a certain number of “electoral votes”.

From NewsForKids.net

New research, led by experts at the University of Nottingham, has found that certain types of medication used to treat diabetes may be effective in reducing alcohol use.

From Science Daily

Related Words

• absolute
• clear
• definite
• genuine
• positive
• real
• safe
• sure
• true
• undeniable

When To Use

What are other ways to say certain?

Someone who is certain of something is free from doubt or reservation about it. How is certain different from sure, confident, and positive? Find out on Thesaurus.com.