crux
noun
[ krʌks ]
• the decisive or most important point at issue.
• "the crux of the matter is that attitudes have changed"
Similar:
nub,
heart,
essence,
most important point,
central point,
main point,
essential part,
core,
centre,
nucleus,
kernel,
the bottom line,
Origin:
mid 17th century (denoting a representation of a cross, chiefly in crux ansata ‘ankh’, literally ‘cross with a handle’): from Latin, literally ‘cross’.