di·a·bol·i·cal 
/ˌdajəˈbɑ:lɪk/ adjective
/ˌdajəˈbɑ:lɪk/ adjective [more diabolical; most diabolical] 1 also di·a·bol·ic /ˌdajəˈbɑ:lɪk/ : extremely evil
▪ a diabolical [=fiendish, devilish] enemy ◊Diabolical often describes a plot, scheme, etc., that is very clever and that is intended for an evil purpose.
▪ a diabolical plot to overthrow the government 2 Brit, informal : very unpleasant, bad, or annoying
▪ The party was awful: the guests were boring and the food was diabolical. [=awful, terrible]
/ˌdajəˈbɑ:lɪk/ : extremely evil ▪ a diabolical [=fiendish, devilish] enemy ◊Diabolical often describes a plot, scheme, etc., that is very clever and that is intended for an evil purpose.
▪ a diabolical plot to overthrow the government
▪ The party was awful: the guests were boring and the food was diabolical. [=awful, terrible]
— di·a·bol·i·cal·ly /ˌdajəˈbɑ:lɪkli/ adverb
▪ a diabolically clever plan
/ˌdajəˈbɑ:lɪkli/ adverb ▪ a diabolically clever plan
