I'm working my way through Kitchen Literacy by Ann Vileisis, which demonstrates that the roots of our ignorance about our food system are deeper than we probably think. It's quite readable and pause for thought. I'm learning a lot.
As one might expect, though, there are errors here and there in the book which prove its point. In an early chapter the author quotes some advice to home cooks for tender mutton - choose, if you can, meat from a cosset withers. She then adds that this is a particularly docile breed of sheep. Wrong. A cosset withers in a pet castrated male (ram or buck depending on where you are doing your sheepherding).
Cosset is a word any of us ought to know from reading 18th and 19th century English novels. But just for the heck of it I googled "withers" and tried the various sources like Merriam-Webster, Britannica, Wikipedia, etc. The only results were for classified ads where folks were selling off their small flocks, as in "2 rams, some withers, mostly ewes".
Withers are the what you get after you harvest and eat the Rocky Mountain oysters.
Why is "withers" a secret term? Is gelding a secret term? Perhaps if we raced rather than sheared and ate sheep, we would know "withers"?