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 polygraphs are unreliable and inadmissible in court, and Hatley maintained her innocence under further questioning.

From Slate • Apr. 6, 2026

While these systems are powerful, they consume large amounts of energy and can still produce unreliable results.

From Science Daily • Apr. 5, 2026

If the NAVs for even a couple of them clash visibly with market reality, it raises questions for investors about whether others might be unreliable, too.

From The Wall Street Journal • Apr. 3, 2026

Goodwin is also troubled by what he labels “stale pricing,” as marks on some positions have a wide variance and can be conservative or unreliable.

From MarketWatch • Mar. 31, 2026

Are you familiar with the phrase unreliable narrator?

From "Confessions of a Murder Suspect" by James Patterson

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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