Source : Webster's Revised Unabridged Dictionary (1913)

Nexus \Nex"us\, n. [L.]
   Connection; tie.

         Man is doubtless one by some subtile nexus . . .
         extending from the new-born infant to the superannuated
         dotard.                                  --De Quincey.

Source : WordNet®

nexus
     n 1: the means of connection between things linked in series
          [syn: {link}]
     2: a connected series or group