unreliable

[ uhn-ri-lahy-uh-buhl ]

adjective

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

   Synonyms: untrustworthy, undependable, irresponsible

unreliable

/ ˌʌnrɪˈlaɪəbəl /

adjective

1. not reliable; untrustworthy

   an unreliable witness

Other Words From

• unre·lia·bili·ty unre·lia·ble·ness noun
• unre·lia·bly adverb

Word History and Origins

Origin of unreliable¹

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

Example Sentences

“In other countries, illegal online drug markets employ the post to send drugs. In Russia, the post is extremely slow and unreliable, so local dealers came up with a new and more efficient way of distribution,” explained sociologist Alex Knorre.

From Salon

Since then dozens of people have got in touch with BBC News, many saying that buses remain fundamentally unreliable.

From BBC

Janette has similar experiences of unreliable service updates in Hereford.

From BBC

Many pollsters have also shifted to using online surveys, but experts said those were known for being unreliable.

From BBC

I know you spent the whole night trying to not look at the New York Times’ historically unreliable needle, which proved to be intolerably accurate this time around.

From Slate

Related Words

• capricious
• deceptive
• dubious
• false
• fickle
• inaccurate
• irresponsible
• treacherous
• tricky
• uncertain
• unsound
• unstable
• untrustworthy