n.
1.a difficult problem
2.a coarse sieve (as for gravel) riddle v.
1.pierce many times
2.set a difficult problem or riddle
3.separate with a riddle, as grain from chaff
4.speak in riddles
5.explain a riddle
Idiom of the Day
have one's heart set against (something)
to be totally against something
My father has his heart set against my trip to Europe.