1. having no trail or path; without a marked route

Examples

• The hikers ventured into trailless wilderness.
• We had to navigate through trailless forest using only a compass.
• The mountain’s north face remains trailless and challenging.
• They explored trailless backcountry far from any marked paths.
• The trailless terrain required careful route-finding skills.
• Rangers warned against entering the trailless area without proper equipment.