【Vicious】 , 【villainous】 ,  【iniquitous】 ,  【nefarious】 ,  【flagitious】 ,  【infamous】 ,  【corrupt】 ,  【degenerate】  are comparable when they mean highly reprehensible or offensive in character, nature, or conduct.

【Vicious】  may imply an addiction to or connection with vice or immorality; usually it suggests moral depravity and is the diametrical opposite of virtuous .

Often the word implies a particular highly reprehensible quality (as ugliness or violence of temper or deliberate cruelty) or it may imply a debasing or complete vitiation by faults, defects, or irremediable conditions.

【Villainous】  is a more condemnatory term than  【vicious】  ; it may suggest specifically qualities which can be associated with a villain, a rascal, or a scoundrel or it may be little more than an intensifying equivalent of  【vicious】 .

【Iniquitous】 is more fixed in its meaning than the preceding terms; it commonly implies the absence of all signs of justice or fairness or a complete indifference to the standards or principles which govern the conduct of civilized or law-abiding men.

【Nefarious】  is often used in place of  【iniquitous】 when one wishes an even more censorious form of expression. The word implies impiety in its deepest sense or a breach of laws and traditions which have immemorially been honored, but it commonly means extremely or flagrantly wicked.

【Flagitious】  and  【infamous】 both imply shameful and scandalous badness or wickedness, but the former is somewhat less rhetorical and more closely descriptive than the latter.

【Corrupt】  (see also DEBASE 1 ) may be applied to persons in an official capacity or to their acts, then implying a loss or lack of moral integrity or probity that makes one accessible to bribes or other inducements to go contrary to sworn duties or obligations or the term may be more generally applied, and then suggests degradation or depravity.

【Degenerate】 stresses a descent and deterioration from a presumed original or earlier high type or condition to one that is very low in the scale morally, intellectually, physically, or artistically.

However it additionally carries so strong an implication of corruption, and so often suggests extreme viciousness that it is generally used to describe what is especially reprehensible and offensive from the historical point of view or in comparison to other members of its class or other instances of the type.