Coaches, referees and gym teachers are probably better authorities than we are, but we've got a feeling that whistles probably aren't very clean.
Think about it. It's a small, tight device that you force your hot, moist breath through to produce a sound. That doesn't sound like the foundation for a sterile environment, does it? It's no wonder a listener named Dan wants to know where the expression "clean as a whistle" comes from.
For many of you, "clean as a whistle” probably means really clean, as in not dirty. For example, "The sink was clean as a whistle after he scrubbed it." Or maybe you'd say something like, "Since she's never even had a speeding ticket, her record is clean as a whistle."
Neither of those examples quite match the historical meaning of this expression.
The first thing you should know is that in this case, "whistle" doesn't refer to the device that a gym teacher wears around their neck. Instead, it refers to the actual sound of a whistle – sharp and loud.
Now think about what "clean" means when you say something like “the locks were cut clean off." What you’re saying is that the locks were cut off entirely and precisely. Also, think about "clean-shaven" or "clean-cut," when "clean" means no unevenness. This is the kind of "clean" in "clean as a whistle."
When this expression first came into the language, it meant "completely." Check out this quote from 1849: "A first rate shot. [His] head taken off clean as a whistle."
It's a brutal example, but you can see how "clean" in this sense means clean-cut or even. You could also think about a branch cut from a tree, clean as a whistle.
At first, “clean as a whistle" was used interchangeably with “clear as a whistle.” However, by 1900, the “clean” version is much more common than “clear” – this has only increased over time.
What's interesting is that at some point, we decided to focus on "clean" as in "not dirty" as opposed to "clean" as in "completely." English Prof. Anne Curzan says, "As I've often said on the show, idioms mean what idoms mean. If people think that 'clean as a whistle' means really clean, then that's what it means."
How do you use this phrase?