Per os, abbreviated as PO, is a Latin term that refers to the administration of medication or other substances through the mouth. There are a few synonyms that can be used to describe this method of administration. One alternative term is oral, which is commonly used in medical settings. Another synonym for per os is through the mouth or via the oral route. When discussing medication administration, the term oral pills or capsules may also be used. It is important to note that per os or oral administration is a common method used for a wide variety of medications, including antibiotics, pain relievers, and vitamins.