Source : Webster's Revised Unabridged Dictionary (1913)

Gigantic \Gi*gan"tic\, a. [L. gigas, -antis, giant. See
   {Giant}.]
   1. Of extraordinary size; like a giant.

   2. Such as a giant might use, make, or cause; immense;
      tremendous; extraordinarly; as, gigantic deeds; gigantic
      wickedness. --Milton.

            When descends on the Atlantic The gigantic Strom
            wind of the equinox.                  --Longfellow.

Source : WordNet®

gigantic
     adj : so exceedingly large or extensive as to suggest a giant or
           mammoth; "a gigantic redwood"; "gigantic
           disappointment"; "a mammoth ship"; "a mammoth
           multinational corporation" [syn: {mammoth}]