1. not able to be trusted or depended on; not consistent or dependable

Examples

• The old car was unreliable and often broke down.
• She proved to be an unreliable witness in court.
• The weather forecast has been unreliable this week.
• His unreliable internet connection made working from home difficult.
• The company’s unreliable delivery service frustrated customers.
• Don’t trust that unreliable source of information.