Whetstone is often associated with the care and maintenance of tools. After buying a new pocketknife, learn to maintain its edge with a whetstone.
Pro Tip 2/3
Not for Cooking
Despite 'whet' sounding like 'wet', a whetstone is not intended for use in cooking. Remember, a whetstone is for sharpening knives, not an ingredient for your stew.
Pro Tip 3/3
Metaphorical Use
Used metaphorically, it implies something that enhances or stimulates. Challenging puzzles are a whetstone for the mind.