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.

Polling in mayoral races is typically pretty unreliable.

From Los Angeles Times • Jun. 1, 2026

The government has often referred to coal as the "ballast stone" for China's energy security: a reliable anchor in an often unreliable global energy market.

From BBC • May 31, 2026

He said unreliable internet was not something which had been stopping passengers from travelling via train - rather, the main issues were fares, delays and cancellations.

From BBC • May 26, 2026

The numbers that researchers have been using to predict which jobs could be lost to artificial intelligence may be unreliable.

From The Wall Street Journal • May 10, 2026

“It isn’t difficult. If you were lying then, why should a court believe you now? There are no new facts, and you’re an unreliable witness.”

From "Atonement" by Ian McEwan

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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