In the German language the word Schmuck means jewelry, adornment. The etymology of the pejorative meaning is a matter of some disagreement. The lexicographer Michael Wex, author of How to Be a Mentsh (And Not a Shmuck), writes that the Yiddish term and the German term are completely unrelated.
A fundamental philosophy of medical oncology, including combination chemotherapy, is that different drugs work through different mechanisms, and that the results of using multiple drugs will be synergistic to some extent.
Adjuvant means additional. Adjuvant chemotherapy is given to patients after primary treatment, when the doctor thinks there is a high risk the cancer will return. After a primary treatment of surgery or radiation, adjuvant chemotherapy reduces the risk of recurrence.