Related Clues:

• Wimbledon's zero
• See 1 Across
• ''A battlefield,'' to Benatar
• Zilch, at Wimbledon
• "__ Makes the World Go 'Round"
• Nil to Navratilova
• Common sign-off
• Serenade
• Sphere of Venus
• Troubadour topic
• No score
• Kind of nest or knot
• Topic of many songs
• Main squeeze
• It is 'resistless in battle,' wrote Sophocles