Related Clues:

• Best seller's number
• A
• Solitary
• Wedded
• 38-Across, to us
• It precedes 'Blastoff!'
• A person
• Sole
• Self starter?
• III
• Microphone tester's word
• More than zero
• DEF, on a phone
• Word that precedes six other answers in this puzzle
• See 32-Across