DIABOLIC
demonic, diabolic, diabolical, fiendish, hellish, infernal, satanic, unholy
(adjective) extremely evil or cruel; expressive of cruelty or befitting hell; “something demonic in him--something that could be cruel”; “fires lit up a diabolic scene”; “diabolical sorcerers under the influence of devils”; “a fiendish despot”; “hellish torture”; “infernal instruments of war”; “satanic cruelty”; “unholy grimaces”
devilish, diabolic, diabolical, mephistophelian, mephistophelean
(adjective) showing the cunning or ingenuity or wickedness typical of a devil; “devilish schemes”; “the cold calculation and diabolic art of some statesmen”; “the diabolical expression on his face”; “a mephistophelian glint in his eye”
Source: WordNet® 3.1
Etymology
Adjective
diabolic (comparative more diabolic, superlative most diabolic)
Showing wickedness typical of a devil.
Extremely evil or cruel.
Synonyms
• devilish, mephistophelian, mephistophelean
• demonic, fiendish, hellish, infernal, satanic, unholy
Anagrams
• biocidal
Source: Wiktionary
Di`a*bol"ic, Di`a*bol"ic*al, a. Etym: [L. diabolicus, Gr. diabolique.
See Devil.]
Definition: Pertaining to the devil; resembling, or appropriate, or
appropriate to, the devil; devilish; infernal; impious; atrocious;
nefarious; outrageously wicked; as, a diabolic or diabolical temper
or act. "Diabolic power." Milton. "The diabolical institution."
Motley.
– Di`a*bol"ic*al*ly, adv.
– Di`a*bol"ic*al*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition