linkage; interrelation; co-movement
Abstract noun expressing that two or more things are linked, move together, or influence each other. Often used in technical, economic, or systemic contexts.
The linkage between exchange rates and stock prices is increasing.
In this system, the interconnectedness of each module is important.
相関 is 'correlation', often statistical; 連動性 is broader, including mechanical or systemic linkage.
Compound of 連動 (linkage, interlocking) + 性 (property, -ness).