This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A source of harm or ruin: Uncritical trust is my nemesis.

n. Retributive justice in its execution or outcome: To follow the proposed course of action is to invite nemesis.

n. An opponent that cannot be beaten or overcome.

n. One that inflicts retribution or vengeance.

n. Greek Mythology The goddess of retributive justice or vengeance.

n. An archenemy

n. A person or character who specifically brings about the downfall of another person or character

n. The principle of retributive justice.

n. A punishment or defeat that is deserved and cannot be avoided.

n. The polar opposite of a character.

n. A righteous infliction of retribution manifested by an appropriate agent.

n. In Greek myth, a goddess personifying allotment, or the divine distribution to every man of his precise share of fortune, good and bad.

n. Retributive justice.

n. [NL.] In zoology, a genus of crustaceans.

n. The 128th planetoid, discovered by Watson in 1872.

n. (Greek mythology) the goddess of divine retribution and vengeance

n. something causing misery or death

"So, how can scientology claim to be a religion if their nemesis is their god."

greek deity    affliction   

bane    rival    archenemy    antagonist    villain    adversary   

nemeses   

nemetic    archnemesis   

justice   

fiance    mentor    policewoman    ex-boss    shipmate    savior    draftee    punisher    front-runner    stepfather