Related Clues:

• It may be tough to crack
• Snack item
• Word with hickory or health
• Enthusi-ast
• Bolt's adjunct
• Extreme fan
• Venture-launching cost
• Fruit-cake ingredient
• Wack-job
• Almond, e.g.
• Bolt attachment
• Acorn, e.g.
• Maniac
• Filbert, for one
• Pecan or cashew