Related Clues:

• At an impasse
• Needing a hint
• Thick, as fog
• Tough to get through
• Like a dumbbell
• Heavy, like some baked goods
• With 51-Across, Presley hit with "glue" in the lyrics
• Like a black hole
• Thick, compact or crowded
• Thick, compact
• Thick as undergrowth may be
• Thick, impenetrable
• At this point 27 across may follow to make one's views unacceptable
• It's a bit thick to have the beasts there over the East
• Around the North the seed is thick