Of, concerning, or characteristic of the devil; satanic.(adjective)
Appropriate to a devil, especially in degree of wickedness or cruelty.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "diabolical" in a sentence
"I think I ` d use the word diabolical to describe the way she lies."
"It is -- well, I came near to using the word diabolical -- to keep them in ignorance."
"Restaurant launch puts my family feud in the past, says Ramsay Gordon Ramsay pledges to put the 'baggage' of his feud with his father-in-law behind him at the launch of his new London restaurant Amanda Knox 'is a diabolical she-devil' Amanda Knox was subjected to a fierce character assassination as she was described as a 'diabolical, satanic, demonic she-devil,' by a..."