nefarious (adj.)
- abject
- abominable
- arrant
- atrocious
- awful
- bad
- base
- beastly
- beggarly
- black
- blamable
- blameworthy
- brutal
- cheesy
- contemptible
- corrupt
- criminal
- crummy
- damnable
- dark
- debased
- degenerate
- degraded
- deplorable
- depraved
- despicable
- detestable
- dire
- dirty
- disgraceful
- disgusting
- dreadful
- egregious
- enormous
- evil
- execrable
- fetid
- filthy
- flagitious
- flagrant
- foul
- fulsome
- glaring
- grave
- grievous
- gross
- hateful
- heinous
- horrible
- horrid
- improper
- infamous
- iniquitous
- knavish
- lamentable
- little
- loathsome
- lousy
- low
- low-down
- lumpen
- mangy
- mean
- measly
- miserable
- monstrous
- nasty
- naughty
- noisome
- notorious
- obnoxious
- odious
- offensive
- outrageous
- paltry
- peccant
- perverse
- petty
- pitiable
- pitiful
- poky
- poor
- putrid
- rank
- regrettable
- reprehensible
- reprobate
- reptilian
- repulsive
- rotten
- sad
- scabby
- scandalous
- scrubby
- scruffy
- scummy
- scurvy
- shabby
- shameful
- shocking
- shoddy
- sinful
- small
- sordid
- squalid
- terrible
- unclean
- unforgivable
- unmentionable
- unpardonable
- unspeakable
- unworthy
- vicious
- vile
- villainous
- wicked
- woeful
- worst
- worthless
- wretched
- wrong
