Related Clues:

• Fourth in a series
• See 56-Down
• Be a busybody
• See 35-Across
• Bridge position
• Sniffer
• Singer Joey with the 60's Starliters
• Just-passing grade
• Low grade
• River to the North Sea
• Not a grade to be proud of
• Plane part
• Scottish river known for its salmon fishing
• D
• Plane section