bubo UK /ˈbjuː.bəʊ/US /ˈbu.boʊ/ noun1 •An inflamed swelling of a lymph node, especially in the armpit or groin, due to an infection such as bubonic plague, gonorrhea, tuberculosis, or syphilis.If a Bubo or Carbuncle appear, set on Leeches not far from it, if it be in an ignoble part; ... — 1661 formsbuboes · bubos