crux

IPA: krˈʌks

The basic, central, or essential point or feature.
The critical or transitional moment or issue, a turning point.
A puzzle or difficulty.
(climbing) The hardest point of a climb.
(heraldry) A cross on a coat of arms.
(astronomy) A distinctive winter constellation of the southern sky, shaped like a cross. It appears in the flags of several countries in Oceania.

Examples of "crux" in Sentences

But what's the crux is what's considered "difficult".
Nor does the Latin word crux automatically refer to a cross while patibulum refer to the cross-beam.
As for the main crux of your question I view commenting on blogs as inherently different from writing a blog.
The crux is that people are paid, mostly, to do difficult and unpleasant things which they wouldn't otherwise do.
The delicious dramatic crux is that the more precarious Mary's prospects for survival become, the more unnerved Elizabeth appears.
The crux is that few banks have been incentivised to voluntarily contribute comprehensive, high-quality information, limiting the scale of such efforts.
The main crux of our authors argument seems to be in this passage: To kill a reader of this newspaper would be to kill a creature richly aware of its environment and full of beliefs and desires, including the desire to continue living.
Updates, 5/16: "It seems silly and grandiose to lavish praise on a movie whose dramatic crux is the recording of a demo tape, and there is some danger that the critical love showered on Once will come to seem a bit disproportionate," warns AO Scott.
While the main crux of the discussion was about the abysmal treatment received, mention was made of computers, and that they are subject to search and seizure, as are jump drives, external harddrives, and all other electronic data storage devices, and they need virtually zero reason or cause to do it.