devilishly

adjective

1. of, like, or befitting a devil; diabolical; fiendish.
2. extreme; very great: a devilish mess.

adverb

3. excessively; extremely: He’s devilish proud.

adjective

1. of, resembling, or befitting a devil; diabolic; fiendish

adverb, adjective informal

2. (intensifier)devilish good food; this devilish heat

adj.

mid-15c.; see devil + -ish. Related: Devilishly; devilishness.