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

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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

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 What remains uncertain A campaign at the lunar South Pole would need to run for months, and no robot team has yet worked that hard, for that long, that far from help. — Wanjiku Chebet Kanjumba, The Conversation, 13 Aug. 2026 Whether homeowners will suddenly stop earning interest on their escrow account is uncertain, Maman said. — Sarah Agostino, CNBC, 13 Aug. 2026 Towards the end there’s a dreamlike montage of uncertain efficacy, though stunning images of Toni and young Adela on a bed covered in vines and grasses are so mesmerizing that the eye wants to linger further. — Jay Weissberg, Variety, 13 Aug. 2026 For parents already uncertain about vaccination, those signals matter. — Krutika Kuppalli, STAT, 13 Aug. 2026 See All Example Sentences for uncertain

Recent Examples of Synonyms for uncertain

Adjective

Back in the early 1980s, amid a volatile chicken market, McDonald’s needed help pricing their nuggets and limiting the risk of menu price fluctuations.

— Sarah Glodek, Fortune, 14 Aug. 2026
Historically, memory has been a volatile, highly cyclical industry.

— Jeff Kilburg, CNBC, 14 Aug. 2026

Definition of volatile

Adjective

The titular gang comprises Mac (McElhenney), a closeted wannabe tough guy; the narcissistic prepster Dennis (Glenn Howerton); Dennis’s chronically unsure fraternal twin, Dee (Kaitlin Olson); and the bar’s buffoonish janitor, Charlie (Charlie Day).

— Paula Mejía, New Yorker, 17 Aug. 2026
Still, stakeholders are unsure what effects a veto override will have.

— Laura Horne, Charlotte Observer, 17 Aug. 2026

Definition of unsure

Adjective

Some have been Ukrainian drones knocked off course by Russian electronic warfare, such as the jamming of navigation signals, which can make their flight paths unpredictable and complicate decisions about whether and where to shoot them down.

— Elsa Ohlen, CNBC, 14 Aug. 2026
Carefully evaluate both options, then, before making a final decision and don't discount the advantages of splitting your funds between both account types, which may be your best recourse in today's still uneven and unpredictable economic terrain.

— Matt Richardson, CBS News, 13 Aug. 2026

Definition of unpredictable

Adjective

Lots of teams will forfeit games because of an ineligible player (barring athletic directors being skeptical of every transfer).

— Eric Sondheimer, Los Angeles Times, 19 Aug. 2026
He's been skeptical of the war, but he's came out recently and said that the war should end.

— Dana Taylor, USA Today, 19 Aug. 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

The person asked for gas money and Bitcoin, requests the family found suspicious because Goods doesn't drive and didn't have a car in Las Vegas.

— Stephen Sorace, FOXNews.com, 19 Aug. 2026
The suspicious em dash—and the easily disprovable notion that only AI used them—was offered as a telltale sign.

— M. C. Mah, Literary Hub, 19 Aug. 2026

Definition of suspicious

Adjective

At the same time, categorical funding can be unstable from year to year due to changing priorities and how much money the state has to appropriate.

— Jason Burns, The Conversation, 17 Aug. 2026
Inside a fusion machine, the plasma can reach temperatures hotter than the Sun’s core while powerful magnetic fields squeeze it into a tiny, unstable space.

— Rupendra Brahambhatt, Interesting Engineering, 16 Aug. 2026