Related Clues:

• Gentle-lamb connector
• "__ matter of fact ..."
• ___ button (Facebook icon)
• Quick ___ flash
• Slippery-eel connector
• Solid/rock insert
• Strong ___ ox
• Hard-rock connection?
• Sick-dog link
• Charles Darwin contemporary Gray
• Tight-drum filler
• ___ formality
• Nutty ___ fruitcake
• Hard/rock center
• Stubborn mule center?