SHOAL, n. 1. A great multitude assembled; a crowd; a throng; as shoals of people. Immense shoals of herring appear on the coast in the spring. The vices of a prince draw shoals of followers. Decay of Piety. 2. A place where the water of a river, lake or sea is shallow or af little depth; a sand bank or bar; a shallow. The entrance of rivers is often rendered difficult or dangerous by shoals. SHOAL, v.i. 1. To crowd; to throng; to assemble in a multitude. The fishes shoaled about the place. 2. To become more shallow. The water shoals as we approach the town. SHOAL, a. Shallow; of little depth; as shoal water.