Nefarious: wicked or evil wicked , evil , sinful , iniquitous , villainous , criminal , heinous , atrocious , appalling , abhorrent , vile , foul , base , abominable , odious , depraved , corrupt , shameful , scandalous , monstrous , fiendish , diabolical , devilish , unholy , ungodly , infernal , satanic , dark , unspeakable , despicable , outrageous , shocking , disgraceful ; my ex was both wicked and evil