Nemesis (Greek: νέμεσις) is a philosophical term first created by Aristotle in his Nicomachean Ethics. The term means one who feels pain caused by others' undeserved success. It is part of a trio of terms, with epikhairekakia (ἐπιχαιρεκακία ) meaning one who takes pleasure in others' pain, similar to Schadenfreude, and phthonos (φθόνος) meaning one who feels pain caused by any pleasure, deserved or not, similar to envy.[1][2]
It is the opposite of pity, as pity is pain at undeserved misfortune.[3]