'Crux' definitions:

Definition of 'Crux'

(from WordNet)
noun
A small conspicuous constellation in the southern hemisphere in the Milky Way near Centaurus [syn: Southern Cross, Crux, Crux Australis]
noun
The most important point [syn: crux, crux of the matter]

Definition of 'Crux'

From: GCIDE
  • Crux \Crux\ (kr[u^]ks), n.; pl. E. Cruxes (-[e^]z), L. Cruces (kr[udd]"s[=e]z). [L., cross, torture, trouble.] Anything that is very puzzling or difficult to explain. --Dr. Sheridan. [1913 Webster]
  • The perpetual crux of New Testament chronologists. --Strauss. [1913 Webster]

Synonyms of 'crux'

From: Moby Thesaurus