Related Clues:

• The very bottom
• Water bed?
• All-time low
• Receiver, as it were
• Acme's opposite
• The lowest point to drain into
• Point opposite the zenith
• Lowest point, or time of deepest depression.
• The lowest part
• Drain to lowest level
• Drain to lowest point
• The lowest point in drain
• Lowest part or underside
• Drain to the lowest point
• Drain into the lowest point (5)