Related Clues:

• Popular cereal or magazine
• Mom's mate
• Common radio fare
• Champagne sound
• Kind of psychology
• Small business co-owner?
• (K) Snap, Crackle and ___
• Soda
• Cork sound
• Spring (for)
• One in a union with 37-Down
• Longest sentence to complete
• Boy Scout rank
• Limb partner
• With 6-Across, online annoyances