British undergraduate degree classification
In the United Kingdom, medicine is usually taught as an undergraduate course, with graduates being awarded a master's level qualification: normally the conjoined degrees of Bachelor of Medicine, Bachelor of Surgery (MBBS, BM BCh, MB ChB, etc.) although at Queen's University Belfast (and universities in Ireland) Bachelor in the Art of Obstetrics (BAO) is added, and at some universities only the Bachelor of Medicine is awarded - all of these have equal standing. Unlike most undergraduate degrees, the MBBS is not normally considered an honours degree, and thus is not classified into first class honours, etc. Students may be awarded "Merits" and "Distinctions" for parts of the course or the whole course (depending on the institution) and "Honours" may be awarded at some institutions for exceptional performance throughout the course (as a grade above Distinction).
Bachelor's degree
Going back in history, the "Bachelor with Honours" (Latin "baccalaureatus cum honore", French "baccalauréat spécialisé") was traditionally taken as the highest undergraduate degree. The program requires at least 4 years of studies, with strong emphasis on the research-based "Honours Seminar Thesis" which is considered approximately equivalent to a formal master's thesis. Universities show the academic degree as well as the possible honours distinction (Latin honors) on the Diploma (e.g., "BACCALAUREATUS ARTIUM CUM HONORE ... CUM LAUDE").