A nexus is a central link or connection. If you happen to be at the nexus of something, you are right in the middle of it, like standing in the middle of an intersection.
Nexus entered English during the 17th century from the Latin word nectere, meaning "to bind or tie." People tend to use this word to describe the point where different things or ideas come together or intersect. In the field of cell biology, a nexus refers to a specialized area of the cell membrane that facilitates communication and adhesion between adjacent cells. By allowing ions and molecules to pass through, these nexuses ensure that tissues can function as a coordinated unit.