like nemesis, but from the wrong side of the tracks;
the DARK side, if you will. there is something more sinister about it, with that silent "g" lurking at the beginning of the word. a nemesis with an ulterior motive. can often be used in place of 'nemesis'.
organic chem is my gnemesis.
he is my gnemesis of hilarity; you said he can be funnier than me, and i don't like it - funny is all i have.
my arch gnemesis, dr. gnat and his gnome henchmen are planning an attack at gnoon today.