the state of being not useful or practical.

अप्रयुक्तता

English Usage: His unusefulness in the project became evident when none of his suggestions were implemented.

Hindi Usage: जब उसकी कोई भी सुझाव लागू नहीं किया गया, तो परियोजना में उसकी अप्रयुक्तता स्पष्ट हो गई।