NEXUS

nex·us -- Pronunciation Key (nekses)
n. pl. -- nexus or nex·us·es

1. A means of connection; a link or tie: “this nexus between the dumbing down of the nation and... George bush”.
2. A connected series or group.
3. The core or center: “The real nexus of the synchronicities was the dream DW had the other night. All the unusual events of the last several days revolve around that dream."

[Latin, from, past participle of nectere, to bind. See ned- in Indo-European Roots.]