...that a cow has "gutters"?
They are also known as "milkers" or maybe even "squirters" or "hangy down thingies"?
I learned this today from my farmer-wanna-be son, when trying to figure out what he meant by "cows have gutters".
I could go all sorts of places with that one, but for your sake, I'll stop. Right now. And pressure wash my brain.