Related Clues:

• Flow slow
• Move like ketchup
• Delta, essentially
• Slugs do it
• Slip through the cracks?
• It builds up in bars
• Behave like goop
• Soft mud
• Boggy earth
• Boggy stuff
• Move like Slimer
• Stick in mud
• Muck and --
• Squishy stuff
• Choke up, in a way