A mediator variable is like a middleman in a process. It comes between two other variables and helps explain the relationship between them. It helps us understand how one variable influences another variable. Full definition
The moderator - mediator variable distinction in social psychology research: Conceptual, strategic, and statistical considerations. (scirp.org)
Compared to simple mediation analysis, multiple mediation analysis may determine which mediator variable plays a more important role in the associations via the methods comparing specific indirect effects. (link.springer.com)
Children self - reported their weekly duration of sports participation, physical activity equipment items at home and the four potential mediator variables. (ijbnpa.biomedcentral.com)