1. the quantity of medicine etc to be taken at one time. A dose is the amount of a substance administered at one time, while dosage refers to the frequency and size of doses over a period. The meaning of DOSAGE is the addition of an ingredient or the application of an agent in a measured dose. A dose is the amount of a drug taken at one time, while dosage refers to how often and how long you'll take the drug for. Following guidelines for dose and dosage can ensure you get effective treatment. DOSAGE meaning: 1. the amount of medicine that you should take at one time: 2. the amount of medicine that you…. Learn more. Dosage is the amount of medicine you take and how often you take it. The recommended dosage for your antibiotic might be one pill twice a day for a week, for example. DOSAGE definition: the administration of medicine in doses. See examples of dosage used in a sentence. DOSAGE definition: 1. the amount of medicine that you should take at one time: 2. the amount of medicine that you…. Learn more. In pharmacology and medicine, dosage refers to the prescribed regimen for administering a medication or substance, encompassing the amount, frequency, and duration of use. [1] In clinical pharmacology, dose refers to the amount of drug administered to a person, and dosage is a fuller description that includes not only the dose (e.g., 500 mg ) but also the frequency and duration of the treatment (e.g., twice a day for one week ).