The term 'FERRY River' is a combination of two words, 'FERRY' and 'River'. The word 'FERRY' refers to a boat or other vessel used to transport people or goods across a body of water. The word 'River' refers to a large natural stream of water that flows in a channel to the sea, a lake, or another river. The crossword solution for this term is 'STYX', which is a river in Greek mythology that formed the boundary between the Earth and the Underworld. It was also believed to be the river that souls had to cross in order to enter the afterlife.