drug 普通用词，含义广泛，可指任何用于预防或治疗肉体上或精神上疾病的药品。用复数形式，多指毒品。
medicine 普通用词，可指药物的总称，也指一切有利于健康的东西。
medication 指医生开给病人用的一切药物，从最简单的阿斯匹林到最复杂的药物。
remedy 普通用词，侧重指对恢复健康有效的药品或治疗方法。
cure 比remedy更强调使身体恢复健康的疗法或良药。
chemical 多指工业或化学中的药品，有时也指医药中的药品。
参考例句
1. Take the medicine every four hours. 每隔四个小时吃一次药。
2. What is medicine? 什么是巫术？
3. Eat something before you take this medicine. 在服用这药之前先吃点东西。
英英解释
n.
1. the branches of medical science that deal with nonsurgical techniques
2. (medicine) something that treats or prevents or alleviates the symptoms of disease
3. the learned profession that is mastered by graduate training in a medical school and that is devoted
4. punishment for one's actions v.
1. treat medicinally, treat with medicine
