UNRELIABLE Synonyms: 70 Similar and Opposite Words

unreliable

adjective

Definition of unreliable

as in erratic

likely to change frequently, suddenly, or unexpectedly I wouldn't count on him to show up for the play—he's pretty unreliable. She drives her car locally, but worries it's too unreliable for longer trips.

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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 unreliable Prosecutors and defense attorneys have clashed over whether DNA evidence revealed the killer or an unreliable investigation where key physical evidence vanished. — Leigh Egan, FOXNews.com, 13 Oct. 2026 Errors can accumulate during calculations, eventually making results unreliable. — Aamir Khollam, Interesting Engineering, 9 Oct. 2026 But few passengers used those services, which were often expensive, slow and unreliable. — Niraj Chokshi, New York Times, 9 Oct. 2026 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 See All Example Sentences for unreliable

Recent Examples of Synonyms for unreliable

Adjective

Has little people skills, lacks self-awareness and can sometimes exhibit erratic behavior.

— Armando Salguero OutKick, FOXNews.com, 13 Oct. 2026
Anthropic’s Dario Amodei and xAI’s Elon Musk scrawled their names in erratic cursive.

— Harmeet Kaur, CNN Money, 8 Oct. 2026

Definition of erratic

Adjective

Stocks are near all-time highs, but the bond market looks much shakier and consumer confidence is decidedly sour even if people do keep spending.

— Evan Clark, Footwear News, 14 Oct. 2026
On offense, the Rays' lineup got to Messick in the fourth thanks to some shaky Cleveland defense.

— Ian Miller OutKick, FOXNews.com, 14 Oct. 2026

Definition of shaky

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

Definition of inconsistent

Adjective

And then there’s Kimberly’s home life, which features an emotionally and physically fragile mom preparing to give birth and an undependable alcoholic father.

— Rob Hubbard, Twin Cities, 25 Feb. 2026
Yasmin, who was ousted from Pierpoint after a tabloid scandal involving her publishing-magnate father threatened to sully the bank by association, has turned to another undependable man for salvation, proposing to an aristocratic failson called Sir Henry Muck (Kit Harington).

— Inkoo Kang, New Yorker, 9 Feb. 2026

Definition of undependable

Adjective

Salton is devious and untrustworthy, but is Batter’s only clear path to a promotion.

— Leigh Haber, Los Angeles Times, 13 Oct. 2026
These small transgressions added up to a sense of ourselves as special, exempt from the rules—but also disliked, distrusted, untrustworthy, apart.

— Literary Hub, Literary Hub, 30 Sep. 2026

Definition of untrustworthy

Adjective

Jeff Shields, a spokesperson for PJM, said electricity demand is growing faster than new generating capacity can come online, while unpredictable weather is leaving fewer opportunities for critical maintenance and construction.

— Brittany Miller, FOXNews.com, 14 Oct. 2026
Loos, who was thirty-one, was known to express displeasure in hot and angry bursts and could be unpredictable.

— Literary Hub, Literary Hub, 14 Oct. 2026

Definition of unpredictable

Adjective

Together, the tools could help accelerate the development of more resilient electric motor systems while reducing the risks associated with critical material shortages, volatile supply chains and rapidly changing global markets.

— Prabhat Ranjan Mishra, Interesting Engineering, 15 Oct. 2026
Daily crude flows are very volatile, with only 3 million barrels of crude transiting Hormuz on Monday while 6 million barrels passed through the strait on Friday, according to Kpler.

— Spencer Kimball, CNBC, 14 Oct. 2026

Definition of volatile

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

Browse Nearby Words

unreliability

unreliable

unreluctant

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Style

“Unreliable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unreliable. Accessed 16 Oct. 2026.

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Synonyms of unreliable

adjective

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