Final answer:
The term "Non Per Os" (NPO) means "nothing through the mouth." It's a medical directive to avoid the oral intake of food or liquids, usually before surgery or certain tests.
Step-by-step explanation:
The term "Non Per Os" or NPO, when translated from Latin, means "nothing through the mouth". In the medical field, this term is commonly used to indicate that a patient should not ingest any substances orally. This typically applies prior to surgery or certain medical tests where an empty stomach is necessary for safety or accuracy reasons.
It encompasses more than just food because it also includes liquids; therefore, 'Nothing to eat or drink' is a practical interpretation in clinical settings. However, it's not as specific as the original Latin phrase, which emphasizes the route of ingestion (through the mouth), rather than the substance ingested. 'Nothing to chew' and 'Nothing but water' are not accurate interpretations of NPO.