The term 'three-pronged fishing spear' is a type of fishing tool used to catch fish. It is also known as a LEISTER, which is a seven-letter word that can be found in crosswords. The three-pronged fishing spear is composed of a long pole with three sharp prongs at the end, allowing fishermen to catch multiple fish at once. It is a traditional tool used by many cultures around the world and is still used today.