Related Clues:

• Set aside
• Held back, as for a rainy day
• Held back
• Available if needed
• Put aside for later
• Held, as for a rainy day
• Kept for emergencies
• On ice
• Kept back
• One might feel spare there, having to keep it
• Like rainy-day provisions
• Held back, perhaps
• At home, book is available if required
• I note ice kept for emergency use
• Concerning answer, it's available for use if needed