adjective cer·tain \ˈsər-tən\

: not having any doubt about something : convinced or sure

—used with it to say that something is known to be true or correct

—used to refer to something or someone that is not named specifically

Full Definition of CERTAIN

:  fixed, settled <a certain percentage of the profit>
:  of a specific but unspecified character, quantity, or degree <the house has a certain charm>
a :  dependable, reliable <a certain remedy for the disease>
b :  known or proved to be true :  indisputable <it is certain that we exist>
a :  inevitable <the certain advance of age>
b :  incapable of failing :  destined —used with a following infinitive <she is certain to do well>
:  assured in mind or action <I am certain they are right>
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>

Examples of CERTAIN

  1. I'm fairly certain that I'll be on time.
  2. <a certain person told me that today is your birthday>

Origin of CERTAIN

Middle English, from Anglo-French, from Vulgar Latin *certanus, from Latin certus, from past participle of cernere to sift, discern, decide; akin to Greek krinein to separate, decide, judge, Old Irish criathar sieve
First Known Use: 13th century

Related to CERTAIN

anonymous, given, one, some, unidentified, unnamed, unspecified
doubtful, dubious, uncertain, unsure
See Synonym Discussion at sure

Rhymes with CERTAIN


pronoun, plural in construction

Definition of CERTAIN

:  certain ones

First Known Use of CERTAIN

15th century

Rhymes with CERTAIN


Next Word in the Dictionary: certainlyPrevious Word in the Dictionary: certAll Words Near: certain
May 28, 2015
fictioneer Hear it
someone who writes fiction
Take a 3-minute break and test your skills!
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears