bubo. a tender, enlarged, and inflamed lymph node, particularly in the axilla or groin, resulting from absorption of infective material and occurring in various diseases, such as lymphogranuloma venereum, plague, syphilis, gonorrhea, chancroid, and tuberculosis.ubo. a tender, enlarged, and inflamed lymph node, particularly in the axilla or groin, resulting from absorption of infective material and occurring in various diseases, such as lymphogranuloma venereum, plague, syphilis, gonorrhea, chancroid, and tuberculosis.