The Oxford Thesaurus An A-Z Dictionary of Synonyms - reprobate adj.

1) unprincipled, immoral, amoral, abandoned, depraved, despicable, dissolute, low, low-life, base, mean, debased, damned, accursed, cursed, degenerate, profligate, shameful, shameless, vile, evil, wicked, villainous, sinful, irredeemable, foul, iniquitous, reprehensible: Such reprobate behaviour soon brought him to the attention of the church fathers. --n. 2) scoundrel, blackguard, miscreant, rake, profligate, rou‚, villain, wastrel, wretch, degenerate, unprincipled person, villain, evil-doer, debauchee, libertine, good-for-nothing, ne'er-do-well, cur, rapscallion, scamp, knave, rascal, US low-life, Colloq scallywag or scalawag: I can't understand what she sees in that old reprobate.