Related Clues:

• ___-timer
• X rating?
• Taps time
• Start of a long distance call
• See 40-Across
• Washington is on it
• Part of a split, perhaps
• It's heard before a liftoff
• 'A Chorus Line' number
• Original Amendments count
• See 34-Down
• More than one
• See 52-Across
• Formula ___
• Company number?