Source : Webster's Revised Unabridged Dictionary (1913)

Inane \In*ane"\, a. [L. inanis.]
   Without contents; empty; void of sense or intelligence;
   purposeless; pointless; characterless; useless. ``Vague and
   inane instincts.'' --I. Taylor. -- {In*ane"ly}, adv.

Source : WordNet®

inanely
     adv : vacuously or complacently and unconsciously foolish [syn: {fatuously}]