the GNU version of the Collaborative International Dictionary of English
adj. Pertaining to the devil; resembling, or appropriate, or appropriate to, the devil; befitting hell or satan; devilish; infernal; impious.
adj. showing a wicked cunning or ingenuity.
adj. extremely evil or cruel; atrocious; outrageously wicked.
The Century Dictionary and Cyclopedia
Pertaining to the devil; partaking of the qualities of the devil; devilish; hence, infernal; Impious; atrocious; outrageously wicked: as, a diabolic plot; a diabolical temper.
Synonyms See list under devilish.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. showing the cunning or ingenuity or wickedness typical of a devil
adj. extremely evil or cruel; expressive of cruelty or befitting hell
Word Usage
"In her presence and before the whole household he repeated his false story, and clung to it with a bitter effrontery that we may well call diabolic, remembering how the nervous terror of punishment and exposure sinks the angel in man."