unserviceable

adjective3

1. •
   Unusable; of no use.

   • And that which was most to our disaduantage, the one halfe part of the men of euerie shippe sicke, and vtterly vnseruiceable. — 1591
2. •
   Of machinery, etc.: not working.

   • During 1936, revealed Pravda, the Gorky plant set itself the task of turning out 12,000 cars. The actual output was 2,500. In one day 24 of 47 cars turned out were tagged “unserviceable.” — 1937
3. •
   Impractical.