Here follows the definition of the words
avenge and
revenge + the difference between
avenge and
revenge.
Both words are about repaying a wrong. The differences between them have to do with grammar and shades of meaning, though there is considerable overlap in meaning, dictated by usage over time. Grammatically speaking,
avenge is a verb only;
revenge is a verb and more usually a noun.
Avenge traditionally relates not only to repaying a wrong but to getting justice on somebody else's behalf as a remedy for that wrong.
Revenge traditionally relates to getting even with an adversary by inflicting punishment or harm.
Though both
avengeand
revenge can be used as transitive verbs with reflexive pronouns,
revenge is commoner in this use: The dictatorship
avenged itself on the partisans' radio station by burning it to the ground; As a victim of a hate crime, she finally
avenged herself on the perpetrators.