(peripheries)
1.
If something is on the ~ of an area, place, or thing, it is on the edge of it. (FORMAL)
Geographically, the UK is on the ~ of Europe, while Paris is at the heart of the continent...
N-COUNT: usu with poss
2.
The ~ of a subject or area of interest is the part of it that is not considered to be as important or basic as the main part.
The sociological study of religion moved from the centre to the ~ of sociology.
N-COUNT: usu with poss