UNCERTAIN Synonyms: 104 Similar and Opposite Words

uncertain

adjective

ˌən-ˈsər-tᵊn

Definition of uncertain

as in volatile

likely to change frequently, suddenly, or unexpectedly the stifling heat would occasionally be relieved by an uncertain breeze

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

as in unsure

not feeling sure about the truth, wisdom, or trustworthiness of someone or something never uncertain of her political beliefs or judgment, she was a decisive and fearless leader

Synonyms & Similar Words

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of uncertain The exact impacts on metro Atlanta and beyond remain uncertain, according to the National Weather Service, but heavy rain, strong winds and some tornadoes could come Friday evening through Saturday. — Caroline Silva, AJC.com, 7 Oct. 2026 But the legislation now faces an uncertain future in the upper chamber. — Chantelle Lee, Time, 7 Oct. 2026 While much of what’s to come remains uncertain, El Nino conditions are fueling a planetary wave that is impacting the West Coast of the United States. — ABC News, 7 Oct. 2026 Jim believes that cuts against the bearish argument that AI compute investments are out of control, with uncertain returns. — Natasha Abellard, CNBC, 7 Oct. 2026 See All Example Sentences for uncertain

Recent Examples of Synonyms for uncertain

Adjective

The researchers focused on volatile elements such as sodium, zinc and potassium, which evaporate easily at high temperatures.

— Sharmila Kuthunur, Space.com, 6 Oct. 2026
Gonzales pointed to the volatile state budget’s dependence on tax revenue from wealthy Californians, some of whom have proactively moved out of the state because of the proposal.

— Seema Mehta, Los Angeles Times, 6 Oct. 2026

Definition of volatile

Adjective

So fraternities promise that kind of friendship and loyalty, and also for young people, 18-year-olds, many of whom are unsure of themselves, fraternities and sororities say this is the way to be popular.

— Richard Hall, Time, 7 Oct. 2026
The department was unsure of the route the aircraft was trying to take, and the crash started a small grass fire that was quickly doused.

— Matthew Ablon, CBS News, 7 Oct. 2026

Definition of unsure

Adjective

Conflict in mining regions, disputed licenses, slow permitting, and unpredictable enforcement have long deterred Western investors, while Chinese operators have been better able to absorb those risks.

— Ruben Nyanguila, semafor.com, 7 Oct. 2026
Long Tiddie Short Story is unmistakably her — honest, unpredictable and incredibly funny.

— Matt Grobar, Deadline, 7 Oct. 2026

Definition of unpredictable

Adjective

In one image, Grande’s Olivia Jones stands beside De Niro’s Byrnes, who wears a decidedly skeptical expression, her hand resting on his German shepherd.

— Alicia Urrea, Billboard, 12 Oct. 2026
Jorge Piñón, an energy researcher at the University of Texas at Austin, is skeptical of the data and noted that only sanctioned Cuban state energy company CUPET has the capacity to store such a large quantity of fuel in one month.

— Nora Gámez Torres, Miami Herald, 12 Oct. 2026

Definition of skeptical

Adjective

Rigorous, blustery winter; winding sleety spring; hot, moist enervating summer; changeful autumn with its dog-days; these are absolutely unknown.

— San Diego Union-Tribune, San Diego Union-Tribune, 1 Jan. 2023
Hers is the kind of face that inspires directors to tight framing — gleaming, as if smoothed from marble, and yet somehow pliant, changeful.

— Jordan Kisner Jack Davison, New York Times, 11 Oct. 2022

Definition of changeful

Adjective

Strong antivirus software can help detect malicious downloads, suspicious links and other threats that may show up in follow-up scams.

— Kurt Knutsson, FOXNews.com, 12 Oct. 2026
Abby became suspicious of Kuehl during a private conversation about possible traitors in the group.

— Lisa Gutierrez, Kansas City Star, 12 Oct. 2026

Definition of suspicious

Adjective

Numerous tornado warnings were also issued for parts of South Carolina and Georgia as the remnants of Isaias move northward and help create supercells of rain and unstable air, according to National Weather Service alerts and forecasts.

— Erika Angulo, NBC news, 11 Oct. 2026
The changes produce new attractors that correspond to stable cell types in the low-lying valleys; unstable gene-activity configurations constitute the high ground.

— Quanta Magazine, Quanta Magazine, 9 Oct. 2026

Definition of unstable

Adjective

Quarterback LaNorris Sellers, receiver Nyck Harbor and defensive end Dylan Stewart are rare specimens, yet each has been inconsistent and unreliable.

— Edgar Thompson, The Orlando Sentinel, 8 Oct. 2026
Alexa Plus is still inconsistent at executing more complicated requests.

— Jennifer Pattison Tuohy, The Verge, 8 Oct. 2026