nemesis

IPA: nˈɛmʌsɪs

(chiefly Canada, US) An enemy, especially an archenemy.
(chiefly outside the US and Canada) A person or character who specifically brings about the downfall of another person or character, as an agent of that character's fate or destiny, especially within a narrative.
The personification of the "fatal flaw" of a dramatic hero in the style of Greek tragedy.
Polar opposite, especially of a literary character.
The principle of retributive justice.
(usually in the singular, formal) A punishment or defeat that is deserved and cannot be avoided; (an instance of) retribution.
(Greek mythology) The goddess of divine retribution.
(astronomy) 128 Nemesis, a main belt asteroid.
(astronomy) A hypothetical star postulated to be orbiting the Sun to explain a perceived cycle of mass extinctions in the geological record.

Examples of "nemesis" in Sentences

The nemesis of the superhero was a cunning and formidable villain
Despite numerous attempts, the detective could not outsmart her nemesis
The two rival companies were constantly trying to outdo each other, each one acting as the other's nemesis
The nemesis of the young wizard proved to be a powerful dark wizard who had been seeking to destroy him for years
The relentless pursuit of justice made the detective's nemesis even more determined to evade capture