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

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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

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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

Tony Hanna, a parent of a Black Bob Elementary School student, said during public comments Thursday night that parents were unsure whether the six schools were the right choice.

— Kendrick Calfee, Kansas City Star, 3 Oct. 2026
Patriot batteries are being deployed, but communities are still developing civil-defense plans, leaving some residents unsure where to take shelter.

— Claudia Ciobanu, Los Angeles Times, 29 Sep. 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

The conservative-majority Supreme Court has been skeptical of environmental regulations in the past, including in a 2022 decision limiting the EPA's authority to regulate carbon dioxide emissions from power plants.

— Arkansas Online, Arkansas Online, 6 Oct. 2026
And while The Atlantic has published largely skeptical coverage of major AI companies and their products’ impact on society, Thompson’s tone, in his podcasts and LinkedIn posts, has been more optimistic.

— Max Tani, semafor.com, 5 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

Mongol rule had been deeply humiliating, and Ming leaders grew suspicious of foreign influence.

— Carl Minzner, Foreign Affairs, 5 Oct. 2026
The move comes as British counter-terrorism police investigate suspicious activity near the Royal Air Force station and amid reports that US commanders received new information about a possible threat involving Iran.

— Georgina Jedikovska, Interesting Engineering, 5 Oct. 2026

Definition of suspicious

Adjective

Climate scientists say as temperatures rise ⁠glaciers in the Himalayas retreat, leaving behind unstable glacial lakes held back by little more than loose rock and ice, above valleys home to millions.

— Reuters, NBC news, 2 Oct. 2026
Volcanoes National Park urged visitors to keep their distance from the unstable cliff edges to avoid putting themselves, or first responders, in danger.

— Charlotte Reck, CNN Money, 2 Oct. 2026

Definition of unstable

Adjective

Even the actors’ bodies exhibit the bland greige produced by the high dynamic range of digital cameras and are flattened by the inconsistent lighting that comes from overuse of green screens.

— Harmon Siegel, Artforum, 1 Oct. 2026
In Finance Give agentic AI fragmented data, inconsistent processes or unclear ownership, and those weaknesses become part of how the technology operates.

— Ari Widlansky, Forbes.com, 1 Oct. 2026

Definition of inconsistent

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“Uncertain.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/uncertain. Accessed 9 Oct. 2026.

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adjective

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