Source : Webster's Revised Unabridged Dictionary (1913)

Stupendous \Stu*pen"dous\, a. [L. stupendus astonishing, p.
   future pass. of stupere to be astonished at. Cf. {Stupid}.]
   Astonishing; wonderful; amazing; especially, astonishing in
   magnitude or elevation; as, a stupendous pile. ``A stupendous
   sum.'' --Macaulay.

         All are but parts of one stupendous whole. --Pope.
   -- {Stu*pen"dous*ly}, adv. -- {Stu*pen"dous*ness}, n.

Source : WordNet®

stupendously
     adv : to a stupendous degree; "stupendously ignorant people"