Possible Clues:

• Make happen at the same time
• Agreement, of a sort
• Adjust to match, informally
• Align, as devices
• In ____, operating correctly in combination
• Match, as audio to video
• "Lip ___ Battle" (pretend singing show)
• 'Lip ___ Battle' (musical game show)
• Lip-__ (mouth the words)
• Extreme features of showy Neo-Gothic harmonise in time