GRIMSAY, an island, in the parish of North-Uist, county of Inverness; containing 269 inhabitants. This is an isle of the Hebrides, lying between North Uist and Benbecula, and is about two miles in length: a large portion of it is covered with heath. A great quantity of kelp is burned on its shores, the manufacture of which is the chief employment of the population. Grimsay is an island only at high water.