1. not able to be relied upon; not trustworthy or consistent

Examples

• The old car was undependable and often broke down.
• She proved to be an undependable employee who frequently missed deadlines.
• His undependable internet connection made working from home difficult.
• The weather forecast has been undependable this week.
• I can’t count on him because he’s completely undependable.
• The undependable bus service caused many students to be late.