"wet one's whistle"の定義と意味

What is the origin of the idiom "wet one's whistle" and when to use it?

The idiom "wet one's whistle" originates from the historical practice of using a whistle or flute-like instrument, often made of bone or wood, to summon a server or bartender at a tavern or inn. Over time, this act was associated with the need for a drink, leading to the idiom "wet one's whistle" as a way to request or consume a beverage.