Final answer:
The abbreviation "PO" stands for "by mouth" when referring to medication administration.
Step-by-step explanation:
The abbreviation "PO" stands for "by mouth" when referring to medication administration. It is commonly used on prescription labels to indicate that the medication should be taken orally, or swallowed. For example, if a prescription says to take a pill "PO" every six hours, it means to take the pill by mouth every six hours.