Related Clues:

• Concentrated
• None too swift
• Excellent, in slang
• 'Sweet!'
• Hardly suited for Mensa
• Big goof
• Drug
• Ignoramus
• Slow to understand
• Not the brightest bulb on the Christmas tree
• Sold-out show
• Thickly populated
• Bubbleheaded
• "Cool!"
• Latest news, slangily