access, admission, admittance, air lock, approach, channel, conduit, corridor, course, ditch, duct, egress, entrance, entranceway, entree, entry, entryway, exit, gangplank, gangway, hall, in, ingress, inlet, intake, means of access, opening, passage, passageway, trench, trough, troughing, troughway, tunnel, vestibule, way, way in