certainty

IPA/ˈsɜːtnti/
KK[sˈɚtənti]IPA/ˈsɜːrtnti/

certainty — noun

  • certaintysingular
  • certaintiesplural

1. the feeling you have when you are completely sure that something is true or will

1.nounB2
Definition

the feeling you have when you are completely sure that something is true or will happen, with no doubt left in your mind

Example

Ravi could not say with any certainty when the bus would arrive.

collocation: with any certainty (negative contexts)

Yara spoke with such certainty that the committee dropped all their objections.

collocation: speak with certainty

Common collocations
  • with certainty
  • with any certainty
  • absolute certainty
  • reasonable certainty
  • state with certainty
  • know with certainty
Synonyms
  • confidence

    similar level of sureness, but 'confidence' can be based on trust or faith; 'certainty' implies more objective assurance

  • conviction

    strong personal belief, often moral or emotional; 'certainty' can be more logical

  • assurance

    feeling of confidence often given by another person; 'certainty' is internally held

Antonyms
  • doubt

    the direct opposite — lack of certainty

  • uncertainty

    the state of not being sure

Grammar Patterns

with certainty

with any certainty

Usage Note

Uncountable; the most common pattern is 'with (any) certainty', especially in negative contexts such as 'cannot say with any certainty'.

Common Mistakes

I have a certainty that he will come' (using 'certainty' as countable when the meaning is a feeling).
I am certain that he will come' or 'I know with certainty that he will come.
The feeling of certainty is uncountable; use the adjective 'certain' or the phrase 'with certainty' instead.

2. a fact or truth that is so securely established that it cannot be questioned or

2.nounB2
Definition

a fact or truth that is so securely established that it cannot be questioned or argued against

Example

Death and taxes are often called the only two certainties in life.

collocation: the only certainty / the only two certainties

The one certainty from the court case was that the old contract had been broken.

Common collocations
  • a certainty
  • the only certainty
  • one of the few certainties
  • treat as a certainty
  • accept as a certainty
Synonyms
  • fact

    a broader term; 'certainty' emphasises that the fact cannot be doubted

  • truth

    similar, but 'truth' can be philosophical or moral; 'certainty' is more factual

  • given

    something taken for granted; slightly less formal than 'certainty'

Antonyms

Grammar Patterns

a certainty that…

one of the few certainties

Usage Note

Countable; this sense refers to a specific fact or proposition that is beyond dispute. Often introduced as 'one of the few certainties' or 'the one certainty that…'.

Common Mistakes

The certainties of modern medicine are constantly changing' (implies settled facts can change, which contradicts the meaning).
The conclusions of modern medicine are constantly changing, but the certainty that germs cause disease is not in doubt.
A certainty is something beyond dispute; use 'findings' or 'conclusions' for changeable knowledge.

3. an event or outcome that is so probable you can rely on it happening, although i

3.nounC2
Definition

an event or outcome that is so probable you can rely on it happening, although it is not absolutely guaranteed

Example

After their perfect season, the team's championship win was treated as a certainty.

collocation: treated as a certainty

Priya's promotion next month is near a certainty after her outstanding results.

collocation: near a certainty

Common collocations
  • near certainty
  • almost a certainty
  • practically a certainty
  • not a certainty
  • treated as a certainty
  • virtually a certainty
Synonyms
  • foregone conclusion

    stronger — implies the outcome is already decided in everyone's mind

  • sure thing

    informal; a bet or outcome that will definitely succeed

  • lock

    very informal, mainly American; a guaranteed result

Antonyms
  • long shot

    informal; something very unlikely to happen

  • gamble

    something risky with an uncertain outcome

Grammar Patterns

near certainty

almost a certainty

not a certainty

Usage Note

Countable; this sense describes a predicted outcome that is extremely probable, not a proven fact. Common modifiers include 'near', 'almost', 'virtual', and 'practically'. Distinguish from Sense 2: Sense 3 refers to what is expected to happen, while Sense 2 refers to what is known to be true.

Common Mistakes

The election is a certainty, but anything could still happen' (contradicts the meaning).
The election is not a certainty yet, so the team kept campaigning.
If you call something 'a certainty' in this sense, you are saying it is extremely likely; adding a contradictory clause confuses the reader.

Word family

Synonym discussion

Sense: noun/1

All four words describe a state of being sure, but they differ in source and strength. Certainty is the strongest — it implies the absence of any doubt, often based on evidence or logical proof (e.g., 'a scientific certainty'). Confidence suggests a positive belief in someone or something, but it can exist alongside some doubt; you can have confidence in a plan while admitting it might fail. Conviction refers to a deeply held personal belief, often moral or emotional — a person speaks with conviction about a cause they believe in, even without hard proof. Assurance has an interpersonal element: it is confidence that someone else has given you, as in 'the doctor gave me every assurance that the procedure was safe.' While certainty is internally held and absolute, assurance is received from another source and may be more tentative.

certainty ↗confidence ↗conviction ↗assurance ↗

Common collocations

Nouns

Adverbs

Phrases

  • with certainty
  • with any certainty
  • with absolute certainty

Prepositions

Etymology

LatinFrenchEnglish

The word 'certainty' entered English from Old French 'certaineté', which came from the Latin word 'certus', meaning 'fixed, settled, sure'. The Latin root 'certus' is related to 'cernere', meaning 'to distinguish, decide, sift' — so the original idea behind certainty is something so clearly distinguished and decided that there can be no doubt about it. The modern senses have stayed close to this core meaning of being settled beyond question.