The term 'tightly crammed' can be described as being WEDGED, which is a 6 letter word. This term is often used to describe a situation in which a large number of objects are placed into a small space, leaving no room for movement. It can also be used to describe a situation in which people are crowded together in a confined area. In either case, the term implies that the objects or people are packed in very closely with no room to spare.