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.

But even they are unreliable: they often get destroyed or jammed, so supply deliveries have been intermittent.

From BBC • May 17, 2026

But many were branded unreliable, faced barriers to work and advancement, and lived under a lasting cloud of suspicion.

From BBC • May 5, 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

Solar panels can also be unreliable because they become dirty, require sunlight and take up space.

From Science Daily • Apr. 19, 2026

Its door was gone and the grass roof looked unreliable, but Nhamo had no choice.

From "A Girl Named Disaster" by Nancy Farmer

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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