Etimology
From Middle English certeyn, certein, certain, borrowed from Old French certain, from a Vulgar Latin unattested form *certānus, extended form of Latin certus (“fixed, resolved, certain”), of the same origin as cretus, past participle of cernere (“to separate, perceive, decide”). Displaced native Middle English wis, iwis (“certain, sure”) (from Old English ġewiss (“certain, sure”)) and alternative Middle English spelling sertane (“some, certain”).
adjective
certain (comparative more certain or certainer, superlative most certain or certainest)
Sure in one's mind, positive; absolutely confident in the truth of something.
Not to be doubted or denied; established as a fact.
Sure to happen, inevitable; assured.
Unfailing; infallible.
Fixed; regular; determinate.
Particular and definite, but unspecified or unnamed; used to introduce someone or something without going into further detail.
(preceded by "a", of a person) Named but not previously mentioned.
(preceded by "a", of a person) Used before the name of someone famous that people are expected to know.
(obsolete) Determined; resolved.
Examples
Synonyms: see Thesaurus:certain
I was certain of my decision.
[…] I think, nay, I may say that I'm sartain, we'll have a hurricane afore morning. It's not the first time I've cruised in these latitudes.
Now that more experiments have been run, the theory is certain and the argument is settled.
[…] the dreame is certaine, and the interpretation thereof ſure.
It is certain that Spain will reach the finals. / Spain is now certain to reach the finals. / Spain is now certain of a place in the finals.
Bankruptcy is the certain outcome of your constant gambling and lending.
[…] death is certaine to all, all ſhall die.
How vain is Virtue which directs our ways Through certain danger to uncertain praiſe!
I have often wished, that I knew so certain a remedy in any other disease
at certain intervals
Then ſaid the Lord vnto Moſes, Behold, I will raine bread from heauen for you: and the people ſhall goe out, and gather a certaine rate euery day, that I may proue them, whether they will walke in my Law, or no.
Every wine has a certain distinctive character which sets it apart from all others.
Each morning, she would see a certain man rush past her window on his way to work.
And it came to paſſe, when he was in a certaine citie […]
About everything that he wrote, serious or sportive, there was a certain natural grace and decorum […]
Synonym: one
Looking inside the cover, they learned that the book had once belonged to a certain R. Jones.
Synonym: one
Since the last British government to make such a proposal was that of a certain Margaret Thatcher, it might not seem unreasonable.
However I with thee have fixt my Lot, Certain to undergoe like doom […]
Related words
synonyms
(sure to happen): unavoidable; See also Thesaurus:inevitable
antonyms
(antonym(s) of "not doubting"): uncertain
(antonym(s) of "sure to happen"): impossible, incidental
(antonym(s) of "known but not named"): particular specific
determiner
certain
Having been determined but not specified.
Examples
Certain people are good at running.
One saint's day in mid-term a certain newly-appointed suffragan-bishop came to the school chapel, and there preached on “The Inner Life.”
pronoun
certain
(with of) Unnamed or undescribed members (of).
Examples
Synonym: some
She mentioned a series of contracts, of which certain are not cited.
[…] certaine of the Jewes banded together […]