Related Clues:

• Breeze source, perhaps
• Two-thirds of Earth
• Buccaneer's bailiwick
• Place for 18-Across
• Sound source
• It makes a sound
• It has a floor but no ceiling
• Kind of lettuce or cucumber
• Mermaid home
• 44-Across's milieu
• Ross or Bering
• Kind of horse or cow
• Briny expanse
• Ionian, e.g.
• Rivers' destination