A nemesis is an enemy or a downfall that cannot be escaped. Meet his nemesis, her old nemesis, the nemesis of the plan.
Strictly it is the downfall rather than the person: Nemesis was the Greek goddess who punished excessive pride, and a nemesis is deserved retribution. The looser sense of an arch-enemy is now much the commoner, especially in sport.
1nounnemesisAn enemy or a downfall that cannot be escaped.
“The champion finally lost to his old nemesis in the final.”
nemesis is a downfall.
From Nemesis, the Greek goddess of retribution, from nemein, to give what is due.
Proto-Indo-European
*nem-
Ancient Greek
Νέμεσις
English, today
nemesis
From the Greek goddess of retribution Nemesis (Ancient Greek Νέμεσις).
Etymology from Wiktionary, CC BY-SA