Related Clues:

• XOXOXO alternative
• Part of some tennis scores
• It makes the world go round
• All you need, per the Beatles
• It's nothing to Federer
• You can't live without it
• Lyricist's subject
• Be very fond of
• Endearing closing
• Object of affection
• Something often fallen out of
• Amour
• Frequent song subject
• All you need, in a song; nothing, on a court
• Heart-to-heart exchange?