What is the X in X-mas?
late 14c., plural buboes, from Late Latin bubo (genitive bubonis) "swelling of lymph glands" (in the groin), from Greek boubon "the groin, swelling in the groin."
bubo bu·bo (bōō'bō, byōō'-)
n. pl. bu·boes
Inflammatory swelling of one or more lymph nodes, especially in the groin.