unreliable

Definitions

Not able to be relied upon or trusted; undependable.

Not consistently good in quality or performance; prone to failure.

Examples

The old car proved to be completely unreliable during our long road trip.

He is an unreliable narrator, so you should question everything he tells you.

Relying on such unreliable data will lead to incorrect conclusions in your research.

Synonyms

untrustworthy undependable fickle erratic inconsistent unstable treacherous

Antonyms

reliable dependable trustworthy consistent steady stable faithful