1. as a devil; in an evil manner - his writing could be diabolically satiric • Syn: diabolically, fiendishly • Derived from adjective: fiendish (for: fiendishly), devilish, diabolic (for: diabolically) 2. in a playfully devilish manner - the socialists are further handicapped if they believe that capitalists are not only wicked but also devilishly clever • Syn: devilish • Derived from adjective: devilish 3.(used as intensives) extremely - she was madly in love - deadly dull - deadly earnest - deucedly clever - insanely jealous • Syn: madly, insanely, deadly, deucedly • Usage Domain: intensifier, intensive