Useless
Futile
Synonyms: Futile, purposeless, vain, to no purpose, unavailing, nugatory, unusable, inefficacious, fruitless, profitless, unachievable, unworkable, kaput, junky, pointless, impractical, in vain, to no avail, bootless, hopeless, ineffectual, impotent, unprofitable, unproductive, Sisyphean, broken, unserviceable, and inutile.
Incompetent
Synonyms: Incompetent, worthless, incapable, inadequate, weak, no good, a dead loss, ineffective, ineffectual, inept, hopeless, bad, and bum.
Example Sentences
This old gadget is useless.
His advice was completely useless.
That broken pen seems useless now.
The outdated map is useless.