Related Clues:

• Squirrel stash
• Filbert, e.g.
• It's tough to crack
• Acorn, essentially
• Tannin-rich nut
• Hard nut to crack?
• Aficionado
• Oak starter
• Bit of hardware
• Enthusiast plus,
• It's often squirreled away
• Squirrel's treat
• Trail mix bit
• Hazel, for one
• Bolt's partner