The word "most trackless" can be interpreted as a lack of route or way, which makes it difficult to navigate. The antonyms of this phrase could be "well-defined," "mapped," "well-marked," "visible," or "charted," meaning that the path has been identified and is easy to follow. Other possible antonyms may include "established," "known," "prescribed," and "fixed," which suggest that the route is entirely familiar or previously explored. In conclusion, "most trackless" refers to an absence of clear direction, while its antonyms convey confidence, ease, and familiarity in following a route.