Infamous by way of being extremely wicked.(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 "nefarious" in a sentence
"In a written statement, President Jonathan said the group, basking in what he called their nefarious success in Jos on Christmas Eve, once again knifed at the heartstrings of a nation celebrating New Year's Eve with this evil and wicked attack."
"This is what we call the nefarious voting tendency called, "In Hop Step"."
"MCINTYRE: Gates had already withstood a flurry of broadsides from committee chairman and ardent war critic Robert Byrd, who railed against the cost of what he called the nefarious infernal war in Iraq."