certain
Americanadjective
-
free from doubt or reservation; confident; sure.
I am certain he will come.
- Synonyms:
- satisfied
-
destined; sure to happen (usually followed by an infinitive).
He is certain to be there.
-
inevitable; bound to come.
They realized then that war was certain.
-
established as true or sure; unquestionable; indisputable.
It is certain that he tried.
- Synonyms:
- clear, plain, obvious, incontrovertible, irrefutable, incontestable, indubitable
-
fixed; agreed upon; settled.
on a certain day; for a certain amount.
- Synonyms:
- determined
-
definite or particular, but not named or specified.
A certain person phoned. He had a certain charm.
-
that may be depended on; trustworthy; unfailing; reliable.
His aim was certain.
-
some though not much.
a certain reluctance.
-
Obsolete. steadfast.
pronoun
idioms
adjective
-
(postpositive) positive and confident about the truth of something; convinced
I am certain that he wrote a book
-
(usually postpositive) definitely known
it is certain that they were on the bus
-
(usually postpositive) sure; bound; destined
he was certain to fail
-
decided or settled upon; fixed
the date is already certain for the invasion
-
unfailing; reliable
his judgment is certain
-
moderate or minimum
to a certain extent
-
to ensure (that one will get something); confirm
adverb
determiner
-
-
known but not specified or named
certain people may doubt this
-
( as pronoun; functioning as plural )
certain of the members have not paid their subscriptions
-
-
named but not known
he had written to a certain Mrs Smith
Usage
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.
Etymology
Origin of certain
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
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Most folks will contact support with questions about connectivity or how certain features work.
From Salon
"When light passes through a diffraction grating, its image repeats itself at regular intervals -- as if it 'revives' at a certain distance. Interestingly, the same effect occurs not only in space but also in time, provided that a regular train of light pulses propagates in a dispersive medium such as an optical fiber," explains Maciej Ogrodnik, a PhD student at the Faculty of Physics, UW.
From Science Daily
Quantum key distribution is valued for its provable security under certain assumptions.
From Science Daily
"A closer analysis shows that the standard description of many QKD protocols is incomplete, which attackers could exploit. Unfortunately, our method shares this vulnerability. We took part in efforts to solve this issue. Our collaborators found that a certain modification of the receiver allows for collecting more data, thus eliminating the vulnerability. The security proof of the new protocol was published in Physical Review Applied, and in our latest paper we discuss its application to our experiment," says Ogrodnik.
From Science Daily
“Overall hiring is steady, but job growth continues to favor certain industries, including health care,” Nela Richardson, ADP’s chief economist, said.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
