Background: Use of the term “drainage” is inconsistent in clinical practice and the existing literature. Objective: The aim of this study was to clarify the meaning of the term and to raise awareness of its proper use. Materials and methods: A selective literature search was performed. Results: Drainage is the process of removing fluid but the term is often used interchangeably with the drain tube, which is often inserted at the same time, which is linguistically referred to as a metonymy. A tympanostomy tube is used for middle ear ventilation and pressure equalization. Lymphatic and abscess drainage are not objects. Conclusion: Standardized technical terminology serves to prevent vagueness and consecutive misunderstandings in a scientific context. This is particularly important in medicine, but is subject to a certain variability in everyday language use.