One who does not know the difference between moral and amoral or right and wrong.
One who believes truth to be subjective is a reprobate.
a low life scum-sucking piece of worthless donkey crap
"Everyone calls my sister in law a reprobate because she sleeps with three different men, leeches money off of me, robs children and beats up helpless homeless people."
A morally unprincipled person.
Example: One who cheats on a test and thinks nothing of it.
One who drinks copious amounts of wine, doesn't care much for people, and loves to use large words when in the presence of low intelligence.
Oh Bruce? Don't worry about him, he's not a threat, he's just a reprobate.