Related Clues:

• Sign on the back
• Get behind
• Sign a check's back
• Approve of
• Give the rubber stamp
• Type of seat
• Furnish with funds
• Do some celebrity backing
• Back, as a candidate
• Spine
• Lend support to
• Speak in favor of
• Give support to
• With 15-Across, 'Same to you, buddy'
• Have great faith in