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Synonyms

unreliable

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

adjective

  1. not reliable; not to be relied or depended on.

    Synonyms:
    untrustworthy, irresponsible, undependable

unreliable British  
/ ˌʌnrɪˈlaɪəbəl /

adjective

  1. not reliable; untrustworthy

    an unreliable witness

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • unreliability noun
  • unreliableness noun
  • unreliably adverb

Etymology

Origin of unreliable

First recorded in 1830–40; un- 1 + reliable

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.

Leah’s book, The Missing Link in Modern Spiritualism, is thorough, yet often unreliable, and obviously one-sided in support of the spirits.

From Literature

"Indonesia's comparatively slower speed stems primarily from unreliable and coal heavy power, slow renewable energy approvals, and grid access uncertainties," as well as drawn-out permit procedures, he added.

From Barron's

But the new car, delayed by the fact Newey did not arrive until March last year, is uncompetitive and difficult, and the engine is slow and unreliable.

From BBC

Despite the prevalence of digestive-health issues, flatulence researchers have been limited to either invasive laboratory studies or self-reporting, which has proven unreliable.

From The Wall Street Journal

In the brutal terrain of female cliques, beauty remains a potent, if unreliable, weapon — one which Amos, her grin a glistening pink, wryly acknowledges and critiques.

From Salon