sweetbreads a butchers’ term which covers both the thymus gland and the pancreas of a young animal, usually a calf (the best) or lamb, although pig’s can also be used. The roundish pancreas, located by the stomach, is larger than the elongated thymus (or throat) gland, and preferred by many. The name thymus comes from a supposed resemblance to the bud of the herb thyme.
All sweetbreads have to be prepared and cooked soon after purchase, since the soft gland tissue deteriorates quickly. Their white colour and delicate texture have conspired to give them a reputation as a food for invalids or convalescents.