uncertain

[uhn-sur-tn]

adjective

1. not definitely ascertainable or fixed, as in time of occurrence, number, dimensions, or quality.

   Synonyms: unpredictable, unsure

2. not confident, assured, or free from hesitancy.

   an uncertain smile.

3. not clearly or precisely determined; indefinite; unknown.

   a manuscript of uncertain origin.

   Synonyms: undetermined, unsettled

4. vague; indistinct; not perfectly apprehended.

   an abstruse novel with uncertain themes.

5. subject to change; variable; capricious; unstable.

   a person of uncertain opinions.

6. ambiguous; unreliable; undependable.

   Her loyalties are uncertain.

7. dependent on chance or unpredictable factors; doubtful; of unforeseeable outcome or effect.

8. unsteady or flickering, as light; of changing intensity or quality.

   Synonyms: irregular

uncertain

/ ʌnˈsɜːtən /

adjective

1. not able to be accurately known or predicted

   the issue is uncertain

2. not sure or confident (about)

   a man of uncertain opinion

3. not precisely determined, established, or decided

   uncertain plans

4. not to be depended upon; unreliable

   an uncertain vote

5. liable to variation; changeable

   the weather is uncertain

6. 1. unambiguously

   2. forcefully

Other Word Forms

• uncertainly adverb
• uncertainness noun

Word History and Origins

Origin of uncertain¹

First recorded in 1250–1300; Middle English; un- ¹ + certain

Idioms and Phrases

see in no uncertain terms.

Synonym Study

Uncertain, insecure, precarious imply a lack of predictability. That which is uncertain is doubtful or problematical; it often involves danger through an inability to predict or to place confidence in the unknown: The time of his arrival is uncertain. That which is insecure is not firm, stable, reliable, or safe, and hence is likely to give way, fail, or be overcome: an insecure foundation, footing, protection. Precarious suggests great susceptibility to failure, or exposure to imminent danger: a precarious means of existence.

Example Sentences

At a point when the world feels more chaotic and uncertain than ever, take the time to make your gift recipient a carefully curated playlist of feel-good music tailored to their tastes.

Read more on Los Angeles Times

When was called on to relieve Blake Snell in the ninth inning, he was uncertain of how he would perform.

Read more on Los Angeles Times

The looming court ruling, he added, is “an extra layer of uncertainty in an already uncertain moment.”

Read more on Los Angeles Times

Its future is uncertain beyond the hope of ushering in a godlike artificial intelligence that might help cure cancer and transform work and life as we know it.

Read more on The Wall Street Journal

With millions of Americans uncertain if they’ll receive their November food benefits, Republican leaders appear more focused on theatrics than governance.

Read more on Salon

Related Words

• ambiguous 
• ambivalent 
• dubious 
• erratic 
• hazy 
• hesitant 
• insecure 
• precarious 
• questionable 
• risky 
• unclear 
• undecided 
• undetermined 
• unpredictable 
• unreliable 
• unresolved 
• unsettled 
• unsure 
• vague