emptiness of mind or lack of thoughtfulness

मन की ख़ालीपन या विचारशीलता की कमी

English Usage: His vacuousness during the discussion was noticeable, as he didn't contribute anything meaningful.

Hindi Usage: चर्चा के दौरान उसकी ख़ालीपन ख़ास बात थी, क्योंकि उसने कुछ भी सार्थक योगदान नहीं दिया।