MAY, ISLE OF, a small island of Scotland, county of Fife, in the Firth of Forth, 6 miles S.E. of Crail. It is about a mile in length, and nearly a mile in breadth, consisting of slaty rock. It affords pasturage for sheep and cattle, and is frequented by great numbers of sea-birds. There is a lighthouse on the island with a fine dioptric light, 240 feet high, and visible from a distance of 21 miles. The cliffs are for the most part steep and perpendicular, rising in some places to the height of 160 feet. Pop. (1851) 18.