Related Clues:

• Plug away
• Effort
• Slave away
• Elbow grease
• Work too hard
• Break one's back
• "Double, double --- and trouble..."
• Travail
• Work like Tillie?
• Proceed laboriously
• Hard labor
• Strenuous exertion
• Put one's nose to the grindstone
• ''. . . ___ and trouble'' (''Macbeth'')
• Trouble partner, in Shakespeare