The term 'TROUT FISHERMAN'S BOOT' can be summarized as a WADER, which is a type of boot that is designed to be worn in shallow water. It is typically made of rubber or neoprene and is used by fishermen who are fishing for trout. The boot is designed to keep the wearer's feet dry while they are standing in the water. The boot also provides protection from sharp rocks and other objects that may be present in the water.