Modifies a noun

• terrain: It requires you to do so on rough, steep, largely trackless terrain that it's hard even to walk on safely.

• waste: I was on a plateau, a trackless waste with the cairns of Drygarn some 2 miles directly north.

• desert: They were also resourceful - some of them managed to obtain three bottles of Johnny Walker in apparently trackless desert.

• forest: An Indian war party, after traversing the trackless forest all the way from Canada, broke in upon their remote and defenseless town.

• wilderness: This leading of the way through the trackless wilderness in snow averaging four feet deep is harder work than one might suppose.

• hill: The ability to cover long distances on trackless hills at speed, irrespective of weather, confers on you a great freedom.