a completely wicked person; a completely morally corrupt person
Up to the age of thirty I lived the drunken and violent life of a reprobate, but when I fell in love with my future wife, I immediately resolved to abandon my former wicked ways.
re (again)#probare (to try, test, prove) (Latin)
reprobate: rep (repeatedly)+rob+ate. a person who again and again robs other peoples food and eats it up has no moral values. reprobate is a person who has no probity