From Tolkien Gateway

A korin was a kind of enclosure according to the early version of the legendarium in The Book of Lost Tales. It consisted in a circular enclosure, which could be formed by a stone wall, thorns or trees, and within there was a green pasture.[1]

The term was Qenya, and despite its similarity with Kôr, it came from a different etymological root. Its Gnomish cognate was gorin or gwarin ("circle of trees").[2]