Metaphor originated from the Greek word, metaphor which simply means to transfer. Analogy on the other hand came from the Greek word, analogia which means proportion. Given these etymologies, metaphor is a figure of speech that actually transfers the meaning of one thing directly on another unit.
Medicines that are taken âas neededâ are known as âPRNâ medicines. âPRNâ is a Latin term that stands for âpro re nata,â which means âas the thing is needed.â. Itâs important to know the difference between daily and âas neededâ medicines.hese instructions should include the following information: 1  How much medicine you can take in a set period of time. 2  When to take your PRN medication. 3  When to take scheduled and PRN medications for a single health problem.
What Does PRN Stand For? (Medical Abbreviation & Meaning) The term PRN is a Latin phrase typically used in the medical field, which means pro re nata, translated, âas neededâor âwhen necessaryâ. Simply put when you hear or see someone use the abbreviation PRN within the medical field they are likely saying, use as needed.