Definitions

unreliable

[uhn-ri-lahy-uh-buhl] / ˌʌn rɪˈlaɪ ə bəl /

ADJECTIVE

not trustworthy, not true

Synonyms

STRONGEST

capricious deceptive dubious false fickle inaccurate irresponsible treacherous tricky uncertain unsound unstable untrustworthy

STRONG

undependable

WEAK

deceitful delusive disreputable erroneous fake fallible fly-by-night furtive hallucinatory hollow implausible inconstant makeshift meretricious mistaken pretended pseudo questionable sham shifty specious unconvincing underhand underhanded unfaithful unsure untrue vacillating wavering weak

Antonyms

STRONGEST

accurate certain clear constant correct definite dependable faithful forthright frank honest reliable right stable steady strong sure true trustworthy truthful

WEAK

responsible

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Concern about unreliable marks is fueling the crisis in private credit, causing investors to dump assets they suspect are overvalued, particularly in the software sector.

From The Wall Street Journal • Apr. 20, 2026

“This letter shows that even utilities like CenterPoint admit that there is no grid emergency and that coal plants are too unreliable, expensive, and polluting to continue operating,” said Ben Inskeep, the coalition’s program director.

From Barron's • Apr. 20, 2026

This idea offers a fresh direction for astrobiology, especially in cases where traditional biosignatures are unclear or unreliable.

From Science Daily • Apr. 15, 2026

The problem for data geeks like Savouri, however, and for investors, is the increasingly unreliable raw material that governments are providing them.

From MarketWatch • Apr. 15, 2026

“They don’t believe me. I’m an unreliable witness.”

From "The Girl on the Train" by Paula Hawkins

Vocabulary lists containing unreliable

STAAR English I: Elements of Literature

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STAAR English II: Elements of Literature 1

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Point of View

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