Related Clues:

• Geometric shape
• Heavenly object
• Field of activity
• Hora feature
• Arena
• Go all around
• Round figure
• It's a ball
• It can follow each word in 17-, 38- and 61-Across
• Sideless solid
• There's simply no end to it
• Baseball, but not football
• Ring's shape
• Enclose
• Bubble, e.g.