Word

crux \KRUHKS\, noun;

Meaning

plural cruxes, also cruces \KROO-seez\:

1. The basic, central, or critical point or feature.

2. Anything that is very puzzling or difficult to explain or solve.

Examples

Ah, and now it was out of the bag, O'Kane thought, the crux of the matter.

--T. Coraghessan Boyle, [1]Riven Rock

The crux of the problem, he said, was "the real disparity between our views and those of the people with whom we have to deal and who are in control."

--John Bierman and Colin Smith, [2]Fire in the Night

Members of an audience cannot stop the actors and puzzle over some difficult expression, as they can when reading the play. The action sweeps you past the crux, which is at once forgotten because you need to keep up with what is being said, not lose the plot by meditating on what has passed.

--Frank Kermode, [3]Shakespeare's Language

Extra

Crux is from Latin crux, "cross, torment, trouble."

Paragraph

What is the crux of life? Has anyone ever understood? Even if someone claims to understand it, can anyone confirm that he is true? Why are we here? What are we doing all this for? What if we die tomorrow? What happens after death? So many questions but perhaps no answers at all. Even the biggest of scientist have failed to answer these questions although research on this has been going on for years now. I wish I could know it. It would help me and many others in my situation live life.