sweetbreads 2

[piattort]

Historically, where did the name'sweetbreads' become used for the thymus gland, and why?

[Quizmonster]

The word was first recorded in a book called Cooper's 'Animal Thesaurus' published in the 1560s. As to the why, the reason is obscure, but Bob's suggestion in an earlier answer seems reasonable. 'Bread' tended to be used to mean 'food' in general in earlier times, too, so 'sweet food' is another possibility.