again from websters:
Main Entry: nex·us
Pronunciation: 'nek-s&s
Function: noun
Inflected Form(s): plural nex·us·es /-s&-s&z /; or nex·us /-s&s, -"süs/
Etymology: Latin, from nectere to bind
1 : CONNECTION, LINK; also : a causal link
2 : a connected group or series
3 : CENTER, FOCUS