noun, noun or participle which takes 'suru'
drinking everything; finishing one's drink
Used when someone drinks all of the contents of a glass, cup, or bottle, often in a single action or to the last drop. Common in contexts like toasting or finishing a beverage completely.
乾杯の後、彼はビールを完飲した。
After the toast, he drank all of his beer.
薬を水で完飲してください。
Please drink all of the medicine with water.