From Longman Dictionary of Contemporary Englishthe cruxthe cruxIMPORTANTthe most important part of a problem, question, argument etcthe crux of The crux of the matter is how do we prevent a flood occurring again? The crux of the problem lay in the lack of equipment. → crux
Examples from the Corpus
the crux• It's the relationship between Trevor and Meriwether that forms the crux of this movie. 