certain

Từ điển American Heritage Dictionary 4th

cer·tain (sûrʹtn)adj.
1. Definite; fixed:
set aside a certain sum each week.
2. Sure to come or happen; inevitable:
certain success.
3. Established beyond doubt or question; indisputable:
What is certain is that every effect must have a cause.
4. Capable of being relied on; dependable:
a quick and certain remedy.
5. Having or showing confidence; assured.
6.
a. Not specified or identified but assumed to be known:
felt that certain breeds did not make good pets.
b. Named but not known or previously mentioned:
a certain Ms. Johnson.
7. Perceptible; noticeable:
a certain charm; a certain air of mystery.
8. Not great; calculable:
to a certain degree; a certain delay in the schedule.pron.
An indefinite but limited number; some:
Certain of the products are faulty.Idiom:for certain
Without doubt; definitely. [Middle English, from Old French, from Vulgar Latin *certānus, from Latin certus, past participle of cernere, to determine. See krei- in Indo-European Roots.] 
Synonyms: certain, inescapable, inevitable, sure, unavoidable
These adjectives mean impossible to avoid or evade: soldiers who knew they faced certain death; facts that led to an inescapable conclusion; an inevitable result; sudden but sure retribution; an unavoidable accident. See also synonyms at sure 
Usage Note: Although certain appears to be an absolute term, it is frequently qualified by adverbs, as in fairly certain or quite certain. In an earlier survey a majority of the Usage Panel accepted the construction Nothing could be more certain.

• Từ đồng nghĩa / Synonyms:
  sure, sealed, certain(p), certain(a)
• Từ trái nghĩa / Antonyms:
  unsealed, uncertain, unsure, incertain