Related Clues:

• IV ___
• What paper towels do to a toilet
• Insomniac’s bane
• IV flow
• Barely flow
• Pipe blocker
• Drain pain
• With 15-Down, hangs on the line
• Get blocked up
• Cause of an icicle
• Folk dancer's shoe, perhaps
• Intermittent trickle
• IV
• Dutch shoe
• Footwear that's hard to run in