As adjectives the difference between decadent and decedent is that decadent is characterized by moral or cultural decline while decedent is removing; departing. As nouns the difference between decadent and decedent is that decadent is a person affected by moral decay while decedent is a dead person.

When used as nouns, deceased means a dead person, whereas decedent means a dead person. When used as adjectives, deceased means no longer alive, dead, whereas decedent means removing. Belonging to the dead. One who has died. In property law, the alternate term decedent is generally used.