insanely

adverbs

in an insane manner

"she behaved insanely"; "he behaves crazily when he is off his medication"; "the witch cackled madly"; "screaming dementedly"

crazily, dementedly, insanely, madly

antonym

is derived from

(used as intensives) extremely

"she was madly in love"; "deadly dull"; "deadly earnest"; "deucedly clever"; "insanely jealous"

deadly, deucedly, devilishly, insanely, madly