"Medium setting" refers to the middle level or average option between different choices or levels of something, such as temperature, intensity, or difficulty. It is neither the highest nor the lowest, but more towards the middle. Full definition
Melt the chocolate in a glass bowl over a pan of simmering water or in the microwave on medium setting at 30 second bursts, stirring frequently until smooth and liquid. (glutenfreealchemist.com)
We definitely recommend using Medium settings, but only if your machine can handle it and still run at 40 FPS or better. (macgamerhq.com)
The rise had to be moved to medium setting for overnight because of the bulk of the two inserts, but it worked fine. (themamaknows.com)