Anatomical passage is a term used to describe a pathway in the body that allows for the movement of substances. The three crossword solutions, VAS (3 letters), ITER (4 letters), and OSTIUM (6 letters), are all related to this concept. VAS is Latin for vessel, which is a tube-like structure that transports fluids or gases. ITER is Latin for path or journey, which is an apt description for the movement of substances through a vessel. OSTIUM is Latin for opening, which is the entry point of the anatomical passage.