Pocket derives from pockete, an Anglo-French word that means “bag” and is related to the French poche and its diminutive pochette. As a landscape term it refers to a recess, cavity, crevice, hole, depression, pit, hollow, or glen. Miners describe small veins or lodes of ore as pockets. And there is pocket ice as well as pocket valleys, pocket beaches, and water pockets. The hidden, secluded, and secretive qualities attached to pocket make it seem a rare, intimate, and mysterious feature of the land or sea.

Michael Collier