Source : Webster's Revised Unabridged Dictionary (1913)

Insanely \In*sane"ly\, adv.
   Without reason; madly; foolishly.

Source : WordNet®

insanely
     adv 1: in an insane manner; "she behaved insanely"; "he behaves
            crazily when he is off his medication"; "the witch
            cackled madly"; "screaming dementedly" [syn: {crazily},
             {dementedly}, {madly}] [ant: {sanely}]
     2: (used as intensives) extremely; "she was madly in love";
        "deadly dull"; "deadly earnest"; "deucedly clever";
        "insanely jealous" [syn: {madly}, {deadly}, {deucedly}, {devilishly}]