certain

[sur-tn] /ˈsɜr tn/
adjective
1.
free from doubt or reservation; confident; sure:
I am certain he will come.
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.
5.
fixed; agreed upon; settled:
on a certain day; for a certain amount.
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
10.
certain ones:
Certain of the members declined the invitation.
Idioms
11.
for certain, without a doubt; surely:
I know for certain that I have seen that face before.
Origin
1250-1300; Middle English < Old French < Vulgar Latin *certānus, equivalent to Latin cert(us) sure, settled (cer- base of cernere to decide, + -tus past participle suffix) + -ānus -an
Synonyms
1. convinced, satisfied. See sure. 4. indubitable, incontestable, irrefutable, incontrovertible, obvious, plain, clear. 5. determined.
British Dictionary definitions for for certain

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
8.
for certain, definitely; without a doubt: he will win for certain
determiner
9.
  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
10.
named but not known: he had written to a certain Mrs Smith
Word Origin
C13: from Old French, from Latin certus sure, fixed, from cernere to discern, decide
Word Origin and History for for certain

certain

adj.

c.1300, "determined, fixed," from Old French certain "reliable, sure, assured" (12c.), from Vulgar Latin *certanus, from Latin certus "sure, fixed, settled, determined" (also source of Italian certo, Spanish cierto), originally a variant past participle of cernere "to distinguish, decide," literally "to sift, separate" (see crisis).

Of persons, "full of confidence in one's knowledge or judgment," from mid-14c. Euphemistic use (of a certain age, etc.) attested from mid-18c. Certainer, certainest were common to c.1750, but have fallen from proper use for some reason. Expression for certain "assuredly" is attested by early 14c.

Idioms and Phrases with for certain

for certain

Also, for sure. Without doubt. For example, I can't tell for certain if this is the right color, or I know for sure that she has a new car. The first term dates from the early 1300s. The variant, dating from the late 1500s, is also used colloquially to express agreement or assert the truth of a statement, as in Mary is really bossy.—That's for sure, or Are you coming to the party?—For sure I am.

certain

see: for certain