Related Clues:

• Don't tread lightly
• Migration
• Trudge (on)
• Arduous trip
• Long, tough trip
• Bond servant
• ''Double, double, ___ and trouble''
• Slog (along)
• Unloved work
• Walk like a lummox
• Trip of much travail
• Walk with heavy steps
• Work one's fingers to the bone
• Long way to hoof it
• Break one's back, so to speak