Related Clues:

• Go down like a rock
• Pile-of-dishes place
• Dirty dishes collector
• Move to a lower position
• Dig as for well
• Consign to less important place - maybe a soccer team
• Drop beneath the surface
• Fall to the bottom
• Plumbing fixture
• Assign to a lower position
• The sort of measure that might get round a horse
• Put it down to having an instance in 31 across
• Put it down to being about an ambassador
• It's wrong to start to go down the drain from this
• Thus might one tell about, for instance, a whole limb one consumed