Adjective
1. liable to be erroneous or misleading;
"an undependable generalization"2. not to be trusted
3. not worthy of reliance or trust;
"in the early 1950s computers were large and expensive and unreliable""an undependable assistant"4. dangerously unstable and unpredictable;
"treacherous winding roads""an unreliable trestle"5. lacking a sense of responsibility