From the Latin for tying a knot — a nexus is where connections converge, sharing its root with connect and annex.
A connection or link between things, people, or events; a central or focal point where multiple elements converge.
From Latin nexus meaning a binding, a tying together, from nectere meaning to bind, tie Key roots: *ned- (Proto-Indo-European: "to bind, tie").
Nexus, connect, and annex all share the same Latin root nectere (to bind). A connection binds things together, an annex binds an addition to a building, and a nexus is where bindings converge. The word has been adopted by both Google and science fiction for its connotation of convergence and interconnection.