nemesis:
(plural: ‘nemeses’, less commonly ‘nemesi‘; for the right pronunciation of this word, please click here and please click here for nemeses)
a person’s very strong and unbeatable opponent or enemy;
an arch-enemy; an arch-rival;
a person whom another person cannot beat or overcome,
e.g.
Superman is always at war with his nemesis, Lex Luther.
Can we say Al-Qaeda is the nemesis of the USA?
All politicians have their lifelong nemeses with whom they have to fight tooth and nail in elections, and some fall, at one time or another, and some come out victorious.
Note: ‘Nemesis’, always with a capital ‘N’, is the name of the goddesses of divine justice and vengeance in Greek mythology, (For an article that explains the Nemesis, the goddess in Greek mythology, please click here.), a ‘nemesis’ is more often used to refer to something that causes or source of misery or death.
For an interesting article that explains the origin of this word, with examples, please click here, for a blog post that shows us how this word is used in the present day scenario, please click here and for a blog post about international nemeses in the IT sector, please click here.


