Over the last few months, I’ve seen both “whet you whistle” and “wet my appetite”, and neither one is true. People’s lips aren’t sharper than they need to be, and people don’t have to eat if they get a good soak. This is how to keep soaked and hydrated in the right places.
Wet Your Whistle
This expression has been used since the 14th century. wet has no hidden meaning. It simply means to make it wet. It comes from the Old English woet “moist liquid.” Whistle can be a bit more difficult to understand. It could refer to someone’s throat or lips (just like “pipe” refers the throat). According to Gary Martin, the Phrase Finder , the story of pub patrons using whistles for more drinks is “completely tosh.” To wet your whistle means to drink to quench your thirst.
Wet Your Appetite
It is almost impossible to whet your appetite. Whetting your appetite is almost the opposite of wetting your whistle. It arouses your thirst and heightens your appetite. Whet is an Old English word that means to make sharper or more acute. It comes from the Old English hwaet adjective which means “brave, bold”, and the Old Saxon hwat meaning “sharp”. Whetstones can be used to sharpen the blades. Appetites can be nourished with tasty morsels or glimpses of desirable or interesting things.
Remember: You want to increase someone’s interest, you are looking to whet their appetite.