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.

Keenan said Robertson's own evidence at the trial had been "wholly incredible and unreliable".

From BBC • Jun. 23, 2026

Choosing depth over volume also matters: one carefully reported long-form article will inform you better than bursts of random, unreliable and emotionally loaded posts on Instagram.

From Science Daily • Jun. 16, 2026

An unnamed Ethiopian assistant professor was selected by ICM for its Midwife Leaders Executive Sponsorship Programme, but was rejected for having an "inadequate financial bank statement and an unreliable purpose of travel", the organisers said.

From Barron's • Jun. 12, 2026

If America’s conventional deterrent is deemed unreliable, fears about the extended nuclear deterrent are even greater.

From The Wall Street Journal • Jun. 7, 2026

My mistake in trusting Dr. Lange plagued me; perhaps my judgment was unreliable.

From "Salt to the Sea" by Ruta Sepetys

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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