unreliable
UK: ˌʌnrɪˈlaɪəbl̩ | US: ˌʌnrɪˈlaɪəbl̩
adj. not able to be trusted or depended on
adj. likely to fail or give inaccurate results
The word "unreliable" is formed by combining the negative prefix "un-" (from Old English "un-", meaning "not") with the verb "rely" (from Old French "relier", meaning "to bind or fasten", ultimately from Latin "religare") and the suffix "-able" (from Latin "-abilis", indicating capability). The progression reflects a logical negation of dependability: "un-" negates the quality of being "reliable" (capable of being depended on).
The old car became unreliable after years of neglect.
His testimony was deemed unreliable by the jury.
Avoid using unreliable sources for your research paper.
The weather forecast is often unreliable in mountainous regions.
She found the app unreliable due to frequent crashes.